Bad Alternator Ground Symptoms

So in order to help you avoid these situations, here is the list of several bad alternator symptoms for you to learn. If a cable is bad then you can have a range of problems that make it seem that other components are causing a problem. When I picked up this new truck I noticed none of the instrument panel worked at all, either. In addition to the location in the pic, the ground connections (at bellhousing, at chassis under the battery, and at the - post) are frequent problem spots. I am working on a 1992 ford f150 XLT 4x4. It is a "24 month" battery that is 4 years old. I took my alternator off and went to Advanced to get it tested and it tested good, then I went to Autozone and got it tested there just to make sure and it also tested good. produce bizarre symptoms that don’t seem to have anything to do with the cause, once you finally find it. One of the most common problems of a faulty alternator is a loosened belt. If the voltage does not change at all with the engine running the alternator is not coming online for some reason. The diodes of the alternator can go bad, failing to transmit the required voltage. If your ground strap is damaged or worn out, #2 - Low Voltage. In other words, the faster it spins the more voltage goes into the car's electrical system. Bad ground connections often cause overheating at the connection points, so check all cable terminations for signs of scorching, burning, or arcing. Unfortunately, bearing replacement is a short-term fix and you may be better off replacing the unit entirely. I would check the ground using the voltage drop method, resistance is not a good way to check it. Headlights are dim or flickering. New battery won't stay charged. I'm going to head down to autozone to have my battery checked, then have my alternator tested. What's happening is that the battery has a bad ground. 5 Symptoms of a Bad Car Alternator If you don't know anything about cars, then you might assume the car battery supplies all the electricity to the vehicle. A bad ground would not cause. 2 volts, then start your car and rev the engine to 2,000 RPM. A diode should allow voltage to pass in only one direction. I would follow cmckenna's instructions, he's very good at what he does. If lower than 28 the stator is bad. Here are a few Simple Tests to determine if these parts are OK, and all that is required is a Digital Voltmeter and probably Two people. Maybe a bad regulator? If it's a bad ground, how can it be found?. If the diode is bad, the alternator will have a short in it and your battery will go dead. i have an 09 wrx with cobb sf intake, nameless muffler delete and a stage 1+ Sf intake tune. What the Home Mechanic Needs to Know about O2 Sensors Download PDF. The sudden death would indicate a possible bad ground. For what it's worth, I have essentially zero faith in autozone/advance/etc battery and alternator testing stations. Voltage drops on the negative side can cause overcharging. So V=10(1) thus making the voltage drop a whopping 10V. An easy test of the thermal switch is to just disconnect the "bullet plug" going to the coil. 5V or more with the engine running, there is a connection problem downstream. When your car's alternator loses ground, it can lead to expensive damage as the alternator surges, posing a malfunction possibility to the voltage regulator inside it. If the diode is bad, the alternator will have a short in it and your battery will go dead. Just replaced alternator again. A good alternator should measure less than. 60 volts and when running it's at 12. Keep the engine running and check the voltmeter again. There may be several wires or just one wire on your alternator, but rest assured that one of them is hot. One of the most common problems of a faulty alternator is a loosened belt. Voltage drops on the negative side can cause overcharging. But how about ground connections under the dash where some one doubled up some add-on ground with a factory. • A single wire with no diode is generally, but not always, an AC only system • A single wire with a diode is generally a DC only system. I had an F150 that had a bad joint at a fusible link in a harness between the alt and the regulator. Also it would be a good idea to check the tightness of the battery cables and alternator cable. if not you have a bad rectifier mark. That broke on me, resulting in my running off the battery with the same symptoms you have. In July of last year, car died on highway, turned out to be a dead alternator. What Are the Symptoms of a Bad Starter. Now that we understand what a head gasket it, it’s important to learn what head gasket failure symptoms look like to avoid higher expenses due to additional engine damage caused by driving with a blown head gasket. While this doesn't always happen, and while sometimes the actual culprit might be your alternator or some other essential component of your car, keeping good track of your battery. Signs & Symptoms of Poor Ground Connection in an Auto Battery No-Start Condition. You can check the amount of A/C voltage leaving the alternator by putting your multimeter leads on the battery (Positive lead on +, and Negative lead on -), with you multimeter set on A/C voltage you should read no greater than. Checking the alternator is another way of checking the condition of your car battery. What’s happening and why. If you feel the vibration only in your seat, it's probably a rear wheel. I still asked them to open it up and change the regulator and it had a bad circuit. a bad batt will still show 12. Reads around 14. Here is a list of the most common signs to check for. Is there a way to test the alternator or regulator so I don't have to replace both. Jeep Patriot Electrical Problems. A bad or failing alternator can discharge your battery, cause issues with your car's electrical systems, or leave you stranded wh. Just wondering what you guys think based on the symptoms. maybe even your alternator belt on my ranchero the radio would quit working and the lights would dim. I have an '06 with 145k miles and think I may have a bad alternator. Assuming my alternator is good, what could cause these problems?. A related alternator failure is the battery warning light illuminating on a random or intermittent basis because the alternator's carbon brushes are sticking in their holders or are worn out. So I changed the battery. 5 , should be 14-14. Check the stator and timer base resistance and DVA output as given below:. Try this when the alternator doesn't appear to be charging and again when it does, in both cases with some electrical load, such as lights, turned on. The regulator connectors has to stay connected or else the engine will not run so you have to poke at the wires. But how about ground connections under the dash where some one doubled up some add-on ground with a factory. Depending on the age of the car, it usually manifests as absolutely nothing happening when you turn the ignition to start. Bad alternator symptoms Five bad alternator symptoms. It is a "24 month" battery that is 4 years old. Often the alternator is blamed for poor charging when the problem isactually bad wiring or connections. If the alternator was bad, then driving to autozone and then back could be enough to drain the battery - particularly since it sat for a few days after that. Well see I have read a few things, one says that if one is bad in an open state it will work as normal just not at 100% which my Red Top might be covering up so I guess off it comes and on goes a replacement so I can bench test it. A starter solenoid is a major component of an automotive starter system. If the starter is working fine, then the chance for a poor ground is somewhat small. You should read a voltage drop of less than 0. If you are experiencing problems with the electrical system, the alternator itself might be fine because the problem could be with one of the belts connected to the alternator. With regulators for the alternator system, voltage limiting is the means of controlling output. Solid as a rock. Correct me if I'm wrong but I think it's just a hot wire, ground wire and a couple bolts holding it in. The simplest of solutions would be to look for bad or worn belts that could cause low rotation to your. A slipping alternator belt can run down the battery as you drive, - if you are driving with your lights on. Get the batt checked and have the alternator fully fielded, that means, get an amp clamp and clamp it to the alt cable, turn all your accessories on, like stereo w/ sub and amp going, headlights, fog lights, whatever you can turn on. ---- I will look into the power sources for these items. If you suddenly show resistance on your meter, then the thermal switch is bad. Below, you have other explanations and advice on this topic (symptoms of bad voltage output, what to do if the alternator voltage output is high or low etc. Manifold Absolute Pressure/Barometric Pressure Circuit High Input. Kohler does make a tester for regulators part number 25 761 20-S but it will set you back about $90. A failing alternator may lead to many serious problems to your car in many ways. Symptoms Of A BAD Alternator. Other possibilities include a failing voltage regulator, or perhaps an alternator pulley that is too small. produce bizarre symptoms that don’t seem to have anything to do with the cause, once you finally find it. 4) Check your ground's, Batt to engine, body to frame ect. Symptoms of a bad TRUCK ALTERNATOR include hard or slow cranking when you try to start your vehicle, lights that seem too dim, and of course the red BATT, ALT, or GEN light glowing on the dash. Alternator electricity is piped through large cables and smaller wires. 2 volts when charged. It will be a lower voltage if the ground is bad. If one diode goes bad, it can put noise on the 12V system which confuses the computer. Misdiagnosis is the No. The alternator charge/warning light comes on while the engine is running. It was towed by Dodge who said it was just a bad alternator (before the recall) and we took it home to replace the alternator. Whether you're an Auto-Tech or not this information will help you to successfully diagnose a bad alternator WITHOUT the use of expensive testing equipment. Even less likely a bad "ground strap" connection the engine to the body. How to determine whether you have a bad Battery or bad Alternator - Duration: 6:21 Hard Start? No Start? Clicks? Find Why Your Car Won't Start | Battery, Alternator and Starter. I can almost guarantee that this will fix your problems. You may want to check the DIC without the car running and see what the voltage is after sitting for a while or overnight--it should be close to 12. If the head unit isn't mounted directly to a solid, GROUNDED metal structure, ground the case of the head unit to the same point that the head unit's ground wire is connected. So I just recently bought a 07c rcsb v6. Hi, I have exactly the same problem with my wife's grand Cherokee, if your alternator and battery are good and all connections are good then it's the voltage regulator in the computer that is bad, this is what is wrong with my wife's jeep, I'm going to fit an external voltage regulator to the body of the car, I'm going to splice the cables from the ones on the rear of the alternator to the. Alternator slippage and undercharging can also be caused by a bad alternator pulley. Of course, a dead battery could be due to a BAD battery, or a loose connection at the battery not allowing the alternator to recharge it. If your ground strap is damaged or worn out, #2 - Low Voltage. Here are the Symptoms of a Bad Throttle Position Sensor One of the more frequent problems with modern vehicles is a bad throttle position sensor (TPS). 2 V with the battery in the bike, so I just removed it and it now seems to be charging like it should. Suffice to say that this thread should remain an "earthy" conversation. One of the most common problems of a faulty alternator is a loosened belt. This makes me lean towards a weak Battery. I suspect your battery is the problem, or a bad ground but if you've had the battery in and out that's probably not it. Testing to see if the alternator is BAD or not, on your Ford (or Lincoln or Mercury) 4. If low, check the charging system for anything that may be reducing the alternator's output (battery and alternator cable connections, ground connections, and voltage output). It happens when car is hot. A starter solenoid is a major component of an automotive starter system. multi-meter start the car and place the probes on the battery posts you should have 12+ volts if your losing volts then it might be the belt or your alternator is taking a dump. Knowing what certain symptoms mean will help you narrow down the possible problems much quicker. what it could be is a bad ground or battery connection so clean all those connections, look for corrosion creeping into the cables at the battery ends, and check and clean the ground cable connections at the engine and frame. put the test leads across the battery terminals with the engine running. Battery cables are made of stranded wires that have an appropriate connector to fit your battery, alternator and starter. Bad alternator? Intermittent power loss at start up,not starting. The 5V reference circuit can […]. I bet that's the one. Of course, a dead battery could be due to a BAD battery, or a loose connection at the battery not allowing the alternator to recharge it. Indicators that warn of an impending alternator problem can include the dashboard warning lights, a growling or whining noise from the engine compartment, and the smell of burning rubber or electrical wires. I did go ahead and replace the battery latter because I felt it could have been affected with the weak alternator for so long. This is one of the more obvious signs of a bad ground, Dim or Flickering Lights. If low, check the charging system for anything that may be reducing the alternator's output (battery and alternator cable connections, ground connections, and voltage output). 2003 ford focus zx3 alternator problems. You might want to clean both ends of the ground cable at the battery, and both ends of the chassis to tranny ground cable. Also it would be a good idea to check the tightness of the battery cables and alternator cable. Besides, the most important ground if you're worried about electronic components is going to be near the passenger side mount, next to the alternator. Ran it for about a half hour to 45 mins, beat the heck out of it several times to 6300, let it idle, get up to operating temp for a while, it ran good. If the car shows continuous discharge, check all the connections at the alternator and voltage regulator. If they are it is probably a bad wire somewhere. The bad diode can cause the circuit to charge even when the engine is shut off, and you end up in the morning with a car that won't start. Assuming my alternator is good, what could cause these problems?. Replace the EGR valve. How to determine whether you have a bad Battery or bad Alternator - Duration: 6:21 Hard Start? No Start? Clicks? Find Why Your Car Won't Start | Battery, Alternator and Starter. Lost ground. Bad alternator symptoms Five bad alternator symptoms. Signs of a Bad Alternator The first and most noticeable sign is that your battery goes dead. Do not only test your customer’s old alternator to verify it is bad, but also test a new or remanufactured alternator before it goes out the door to verify it is good. When the previous owner had it, he replaced the battery, and alternator with Napa units. This makes me think the voltage regulator may be bad. Porsche 997: Does My Car Have Alternator Cable Issues? Early 997s have a very common issue that mimics a bad alternator. There could be a variety of bad alternators symptoms, but the most common or obvious ones will be discussed below. I'm thinking I have a bad alternator, and possibly a bad battery now. This makes me lean towards a weak Battery. I would check the ground using the voltage drop method, resistance is not a good way to check it. An easy way to find out is start your car and disconnect your negative terminal, if the car shuts off it's your alternator. It is the alternator. Many times technicians will have the tendency to overcharge refrigeration systems. A bad ground wire can cause a lot of strange symptoms with your cars electrical system. Variability in the failure mode ranges from no output, reduced output, and/or a fully shorted to ground condition. If you suddenly show resistance on your meter, then the thermal switch is bad. If the ground Voltage is high, there's a bad grounding situation. the frame or body of the car. Car Audio Noise. Do the symptoms I described above fit with having a bad alternator, if so, where do you recommend finding a replacement?. One of the most common problems of a faulty alternator is a loosened belt. Hey guys I'm new to this forum, just recently traded my 2003 Chevy Silverado 2500HD 6. Visual cues. Why Do Head Gaskets Blow?. The ignition coil receives a voltage of 12V from the car's battery and multiplies it to a higher voltage level. If you feel the vibration only in your seat, it's probably a rear wheel. Understanding the warning signs of car alternator problems will help to avoid expensive repairs and inconvenient breakdowns. A =LOT= of wierd engine behavior is caused by poor grounds, especially on early XJ's!. Symptoms of Bad or Failing Battery Terminal Ends. Starter Clicks Several Times and then the Car Evenually Starts!! By BassHead1990 , May 23, 2013 in Engine and Performance - Anything for that couple extra horses! Reply to this topic. Another common symptom is a intermittent sound or sound that cuts out frequently. The article I wrote on how to locate a short-to-ground using a lab scope (November 2015) did not cover how to diagnose a computer's 5V reference circuit that's shorted to ground. Symptoms of a bad alternator are dim lights, service engine light, odd noises, electrical issues, engine stalling and a dead battery. However, here is a list of the most common symptoms associated with a bad engine speed sensor:. Paying attention to the 10 trouble signs on this list can make it a little easier to diagnose car trouble caused by the alternator. Case closed. This noise indicates that the system either has a bad ground, defective head unit, defective amplifier, bad RCA cables, improper installation, or a problem in the vehicle’s charging system. Should be easy to tell. Rick Muscoplat, an automotive expert at Family Handyman, will show you how to test your alternator. While driving, multiple warning lights (seat belt, oil, alternator, etc. they will usually produce a few symptoms that can notify the driver of a Another common symptom of a bad battery terminal is loss of. Troubleshooting car battery problems can sometimes be quite vexing. This makes me lean towards a weak Battery. Fortunately, it’s fairly easy to recognize the symptoms of a bad ground strap. Just wondering what you guys think based on the symptoms. Notice I didn't say that the alternator's primary job is to recharge the battery. Signs of a Bad Alternator The first and most noticeable sign is that your battery goes dead. The alternator is bolted to the engine so it is unlikely to be a ground issue. The alternator charge/warning light comes on while the engine is running. For what it's worth, I have essentially zero faith in autozone/advance/etc battery and alternator testing stations. What Are the Symptoms of a Bad Starter. I suspect your battery is the problem, or a bad ground but if you've had the battery in and out that's probably not it. The component that has the highest failure rate on most alternators is the Bridge Rectifier. Could be a bad alternator or bad battery, or a bad ground. The headlights probably have a bad ground. In other words, the faster it spins the more voltage goes into the car's electrical system. Signs of a Bad Wheel Hub. When the alternator is going bad, 4. Symptoms Of Bad Ficm On 6 0 Engine PDF Download. next whould be to check the wires to the alt. This ignites the fuel and makes your vehicle run. What’s happening and why. CUCV alternator symptoms, diagnosis and fix. Hey guys I'm new to this forum, just recently traded my 2003 Chevy Silverado 2500HD 6. Get the batt checked and have the alternator fully fielded, that means, get an amp clamp and clamp it to the alt cable, turn all your accessories on, like stereo w/ sub and amp going, headlights, fog lights, whatever you can turn on. The symptoms might start out being minor, but they could progressively get worse if you don’t do anything about the ground wire. If it is the same voltage as the battery then fusible link likely good. I waited like 15min and finally started up and luckily drove it home and finally died again. At rest, a fully charged battery should be 12. I guess once it got hot enough it just was not efficient any more. Solution: I felt that because the car ran on the alternator when running I had to start there. Is it the alternator or a bad ground? (2003 Volkswagen Jetta) My 2003 Jetta has these intermittent electrical gremlins where the interior lights (dash,doors,radio,etc. Get shopping advice from experts, friends and the community! No. Diagnosing voltage drop Electrical automotive troubleshooting One of the most rampant electri-cal maladies showing up in automotive service bays today is the phenomenon known as volt-age drop. A bad battery cell can cause the alternator to over-charge the good battery cells. One of the immediate things that you may notice is that the lights on your dash and inside your car dim at random times and then seem to work again. It could be another problem that presents similar symptoms, so look into other possibilities—such as signs your alternator is bad—as well if you want to get to the bottom of the issue. Alternators power the small engine while it is running, keeping the battery charged by circulating power back through the system. Occasionally, a symptom of this issue might be brighter lights, as the alternator produces more energy to overcome the resistance in a bad wire or a broken or loose connection. Defective alternator diode. 6 Symptoms of a Failing Alternator If you experience flickering headlights, stalling or strange noises when driving, your car isn't haunted; chances are it's just a failing alternator. A related alternator failure is the battery warning light illuminating on a random or intermittent basis because the alternator's carbon brushes are sticking in their holders or are worn out. Computer failure: bad alternator (for which there is a recall) malfunctioned, while the vehicle was in motion, and at the same time, damaged the computer, causing the engine to shut down. I've been having problems with my '98 C5. Could a bad ground be killing them or the ELD (electronic load detector). You may have to register before you can post: click the register link above to proceed. Some common causes of alternator problems include wear and tear, a bad battery, a lost ground and a slipping belt. If you're installing a high output alternator, larger gauge battery cables, ground straps and charging wire may also be required. Flickering or dim headlights are a strong signal 3. So V=10(1) thus making the voltage drop a whopping 10V. A bad ECU may actually just be a bad ground at the ECU, so be warned. I thought this was just maybe a bad ground somewhere so I didn't think much of that either (check gauges light was still on at this time). I have an '06 with 145k miles and think I may have a bad alternator. If the voltage is still wrong after replacing alternator and battery check the voltage regulator connected to the alternator. Your Jeep Grand Cherokee Alternator converts engine power into electrical power and transfers it to the battery. Make absolutely sure the ground paths from regulator back to the engine are clean, dry and not partial. In order to clear the problem, I turn the car off, jump it from the wife's car and bingo, it starts right up and the light is out. by a weak battery, dragging starter, bad battery cables or a mechanical problem inside the engine. Signs of a Bad Alternator The first and most noticeable sign is that your battery goes dead. 2014-2017 Dodge 5. No series of clicks, just silence. If it is, check from low or high beam to ground in plug. So in order to help you avoid these situations, here is the list of several bad alternator symptoms for you to learn. The large ground straps to the engine being bad would cause the engine to die when this happens. When car is off it's at 12. Whether you're an Auto-Tech or not this information will help you to successfully diagnose a bad alternator WITHOUT the use of expensive testing equipment. The large ground straps to the engine being bad would cause the engine to die when this happens. Over time, the vapor can begin to corrode the terminal and cause corrosion to build up. If there's a problem with the battery where the reference voltage is very low, the alternator will try to recharge the battery. I have seen known bad batteries and alternators test good and vice versa. what it could be is a bad ground or battery connection so clean all those connections, look for corrosion creeping into the cables at the battery ends, and check and clean the ground cable connections at the engine and frame. Battery cables are made of stranded wires that have an appropriate connector to fit your battery, alternator and starter. This is done by jumping full battery or full ground to the generator or the alternator field post. I would check the ground using the voltage drop method, resistance is not a good way to check it. If they are it is probably a bad wire somewhere. You may want to check the DIC without the car running and see what the voltage is after sitting for a while or overnight--it should be close to 12. If low, check the charging system for anything that may be reducing the alternator's output (battery and alternator cable connections, ground connections, and voltage output). It’s been almost a month now and so far so good. I'll check it out later of course. Signs of a bad alternator. An alternator is a very important part of the electrical power system of a car. When the alternator is charging, the switch is open and the lights are off. Wouldnt start, like it was a battery problem. what it could be is a bad ground or battery connection so clean all those connections, look for corrosion creeping into the cables at the battery ends, and check and clean the ground cable connections at the engine and frame. I agree that a bad diode pack will drain a battery. Does a bad alternator lead to power drain from the engine. But more likely a field connection or wire (the small wires on the back of the alternator), the main alternator output (look at where it goes through the firewall), the voltage regulator out, or maybe even the voltage regulator module not being well grounded. Indicators that warn of an impending alternator problem can include the dashboard warning lights, a growling or whining noise from the engine compartment, and the smell of burning rubber or electrical wires. Signs of a Bad Alternator The first and most noticeable sign is that your battery goes dead. You need to look somewhere else. I have bought a multi meter to check the voltage and stuff but dont know how to use it. Bad switches more commonly tend to have a hard time starting up, but then will run smoothly and at full power once the connection is made. If the car shows continuous discharge, check all the connections at the alternator and voltage regulator. Symptoms of faulty EEC Relay???? Computer voltage from pins 37 and 57 is good, replaced dizzy with Motorcraft unit with newer TFI it had on it. If the ground Voltage is high, there's a bad grounding situation. These are the basic symptoms of a bad alternator:. '95 850GLT Bad Alternator Symptoms. In some cases, the starter motor will kick in after the second or third attempt; in others, it will fail altogether. See our lemon odds and nada odds page to see vehicles with no repairs or vehicles with more than three repairs. As for the Alt, replace the whole part if it checks out bad that way you know what you got. When car is off it's at 12. Starter Checks An engine that won't crank may have a bad starter, or it may have another fault such as a bad starter solenoid starter drive, a problem in the ignition switch circuit, the park/neutral or brake safety. By Farside, June 5, 2004 in Wiring, Electrical and Installation Help alternator, or battery. One of the first symptoms of a bad or failing alternator is the need to jump start the vehicle on a regular basis. a bad ground wire can ruin an alternator by not completing the circuit. 1998 Ford Explorer Sport battery dies just from listening to music for half an hour with the engine off is the voltage across the battery terminals with the car running dependent on whether the battery is good? im getting 12. Still if nothing else makes sense, you can do worse than to go through the car checking and cleaning the ground connections. This causes the alternator or generator to charge at full output when rotated. you could get a cap, however it. • IG is the ignition input that turns on the alternator/regulator assembly. Therefore, it is important to recognize the symptoms displayed by a faulty knock sensor to prevent the engine from severe damage. If you are experiencing problems with the electrical system, the alternator itself might be fine because the problem could be with one of the belts connected to the alternator. The alternator isn't designed to recharge a dead battery. This makes me think the voltage regulator may be bad. '95 850GLT Bad Alternator Symptoms. produce bizarre symptoms that don’t seem to have anything to do with the cause, once you finally find it. If you measure more than that, you have a bad connection in between those two points. Also many of the Ford ones ground through the case so make sure the area it bolts to is clean at least around one of the bolts. The voltage limiter is inside the voltage regulator. Bad switches more commonly tend to have a hard time starting up, but then will run smoothly and at full power once the connection is made. Usually the sound will get worse when you turn to the side with the good hub, and will lessen when you turn to the side with the bad hub. An alternator’s main job is to keep up with the electrical demands being placed on the battery while driving. A "bad ground" is not apt to affect engine performance, because if that ground is bad the engine is not likely to start. If you have a newer battery, but your car won't start, you may have a bad alternator. Grounding testers, like the Fluke 1623 and 1625, are indispensable troubleshooting tools. The Jeep Grand Cherokee Alternator is a machine that converts electricity to fuel the ignition. Hi, I have exactly the same problem with my wife's grand Cherokee, if your alternator and battery are good and all connections are good then it's the voltage regulator in the computer that is bad, this is what is wrong with my wife's jeep, I'm going to fit an external voltage regulator to the body of the car, I'm going to splice the cables from the ones on the rear of the alternator to the. The new alternator did not test bad, so I decided to insulate the ground wire as described above. The dash lights also flicker with bass in the car. This makes me think the voltage regulator may be bad. Assuming my alternator is good, what could cause these problems?. If the head unit isn't mounted directly to a solid, GROUNDED metal structure, ground the case of the head unit to the same point that the head unit's ground wire is connected. Yep, positive post on alternator to ground while engine running. nany ideas what may be causin 1 Answer. Engage the brake, choke the throttle, turn the key and you should hear the satisfying rumble of your riding lawn mower's small engine. If battery, alternator and power regulator are OK, test wiring to find out if there is a short to ground that is draining the battery while you drive. Ground issues are very important on highly sensitive devices, but you have to keep in mind that these components are all designed for some extreme tolerances. We called Chrysler and they didn't help at all but to tell us to take it to the dealership which they was closed so I fixed it my self and all it was is a bad alternator. Top 5 Symptoms of a Bad Negative Battery Cable. Sometimes there is a smaller wire coming off the battery and is grounded to the fender well or some where thats a ground point. I thought this was just maybe a bad ground somewhere so I didn't think much of that either (check gauges light was still on at this time). A good tip is to unplug, inspect and plug back in the main harness plug back at the engine. Symptoms of a bad voltage regulator might include a dead battery, dim or pulsing dash lights, or erratic engine performance. The sunshine should illuminate once the engine starts. 5VAC, if you get more, your rectifier bridge on your alternator. If you have a newer battery, but your car won't start, you may have a bad alternator. Another symptom of a bad or failing cable is the presence of corrosion on the terminals. Symptoms and Signs of a Bad Alternator - Noises, Smells Buyautoparts. all my electricals work just fine when the car is on and running, perfect idle, lights and ac work well. If a diode is bad there could be a lot of AC on the alternator line. Then, when the RPM is over 1000 to 1500 RPM, moving or not, the voltage jumps to 14+ volts. The Volt meter shows about 14V at idle but when I hit the gas the meter instantly drops and the truck will die, and have to be jumped, unless I let off the gas which sounds like a ground issue to me or a bad alternator and the tests at the local parts stores aren't worth a damn because it tested good twice. If you have 27 volts a/c. Symptoms of a charging problem include a low battery, dim headlights, hard starting or a charging system warning light. Re: Symptoms of bad rectifier? Originally posted by nphilbro View Post So, to be clear, running with a bad rectifier can do serious damage to other ignition components over time?Am I safe to assume the sudden power loss at cruise speed when adjusting the trim correlates to a bad rectifier-large power draw the battery can't support on its own. If the ground Voltage is high, there's a bad grounding situation. Causes of a Bad Alternator. He said one day it just stopped starting. With having TWO bad alternators in a row I can now do a complete alternator change start to finish in one hour with this method. Understanding the warning signs of car alternator problems will help to avoid expensive repairs and inconvenient breakdowns. if not you have a bad rectifier mark. How to determine whether you have a bad Battery or bad Alternator - Duration: 6:21 Hard Start? No Start? Clicks? Find Why Your Car Won't Start | Battery, Alternator and Starter. For what it's worth, I have essentially zero faith in autozone/advance/etc battery and alternator testing stations.