Psp charging problems.

Charging problems

• QUESTION: i have a 96 Cadillac deville with charging problems. It starts up with 13-14 volts but while driving it fluctuates up and down, eventually working its way down to low voltage. on occasion it may go as low as 9.0 volts and then shoot back up to 13. The alternator is about 5 months old and has been tested and retested by several shops always coming back good. The battery is 4 months old and is a 1000 cca duralast gold battery. The wires all appear to be in good condition and the PCM brand new. Every mechanic thar has looked at can not think of what else could possibly cause the problem. HELP! Already tried: New Battery (1000 CCA) New alternator Replaced Ground (used) Repaired electrical cluster (by dealer) New PCM Checked/cleaned all wires Checked fuses Other electrical work (not sure of details) ANSWER: Hello, Without being at the car, I am at a huge disadvantage and I can only venture to guess here, but I would go back to looking at the alternator. It doesn't matter how many times it has been tested with the results of no problems, is it being tested when this intermittent problem appears? I am thinking that something in the alternator has a crack in it, where it starts off charging good and then something while driving is opening the connection and then closing again to bring it back to a full charge condition. You are dealing with two different issues when testing the alternator. When being tested, the vehicle is stationary and not moving down the road. Let's say you have a crack in a pc board. If stationary, everything appears fine, however when moving and heating up, the crack separates causing the system not to charge. Then while driving down the road, another bump puts the broken connection back and you get a surge in charge. Unless you can test every activity while the car is moving which you can't any of the charging system testing once the car is parked is moot. It means nothing to me if the alternator is new. New components fail too. My question would be; why was the alternator, battery, ecm changed in the first place? Were you chasing this intermittent problem or was something else wrong? You stated you changed the alternator 5 months ago. Has this charging system problem been gone for five months and just occurred or reoccurred? Something while driving is causing this situation while the vehicle is moving and heat may or may not have something to do with it. Please tell me why all these parts were changed and if there was a difference, even temporarily for a period of time. http://www.autotheftexpert.com ---------- FOLLOW-UP ---------- QUESTION: The alternator was originally going out as said by a mechanic so I had it changed. The car ran ok for a while (maybe 2 weeks) then charging problems arose again. So I took it to a dealer. The cluster was then diagnosed to be the problem by the dealer, it only seemed to make a difference for one day, then the problems arose again, the dealer then said there was a faulty battery issue and that its not receiving a charge because whenever they hooked the ground a jump box the problem would cease. The battery was changed, and the problems eventually arose again, so I had it diagnosed by a local shop and they tested the alternator to be fine, and said the battery was no good. I then took the NEW battery back to autozone and it did in fact test as a bad battery. So they swapped me out and it ran fine for 2 weeks. Finally it caved again and I tried new deeper battery posts and a new ground. It seemed to charge up one the ground was connected. But shortly after, the fluctuation began. So I had an electrical guy look at it, as well as a nearby shop. They came to the same conclusion; a corroded wire or a PCM error. So that's why I changed the PCM. And it made no difference. ANSWER: Hello, As I said though, unless you can replicate the issue in which someone can actually test for a problem, it's not going to get fixed and you are going to throw money at it. I realize its a real inconvenience to you, but your techs even hold a tremendous advantage over me because they are physically at the car. One thing that came true and I was right--new parts fail--your battery as an example. I would be getting as frustrated as you. It's obvious that you have gone out of your way to let these people fix your real very serious problem. I do really question as to how so many things were bad at one time (period you were trying to repair the same symptom). It kind of sounds that they were fixing the problem on a guess. In my 30+ years of being a tech, I have never heard of such a nightmare with a charging system! It's usually the complaint, then then the diagnoses, then the repair and then it's fixed. If a problem is intermittent, I would drive the car and hook equipment to the car and try to replicate the issue and hopefully the diagnostics would tell me what is wrong, so I would change the failed part and fix it right the first time. I am wondering if the surge of voltage caused a cascading affect and burned out the computer. In an example that is easy to understand is Cadillac engine overheating. The car overheats and the tech says it needs an expensive repair of a head gasket and that will fix the over heating. This tech should not ever be allowed to work on any Cadillac engine! The blown head gasket is the affect of over heating resulting from a cascading affect from something else causing the engine to over heat. Changing the head gasket will make the engine fine for 5-10 minutes of driving before the head gasket(s) blow again because the original problem causing the over heating was not repaired. I use this as example like maybe the cluster and pcm are similar to the head gasket in my story. The surge of voltage as you stated, could have very well have burned out the computer and the cluster and battery which were not the original problem. Even with computerized cars the charging system in your Cadillac, is still rather simple. You have the alternator, wiring and battery, with a volt meter in the cluster. There is not much there. Its not complicated-honest. I assume this problem happens while driving only. This means the difference is movement. I think I gave this example before, but if a diode mounting or a voltage regulator, rectifier bridge has a hairline crack that separates under heat and movement, and say you hit a bump, after dropping to 9 volts and then surges past 13 volts, you are going to burn up associated parts. I sure think you have something bad in the alternator. I don't care if its checked when working normally. Most alternators are guaranteed for life and I would contact the guy who changed it. If he says he finds no problem, explain about the intermittent problem you cannot recreate and all the parts you have changed because of the voltage surge and see what he has to say. Let me know if a new alternator you should not have to pay for works out. http://www.autotheftexpert.com ---------- FOLLOW-UP ---------- QUESTION: He cleaned the ground wire and put it in a different spots and it works pefect!it has yet to drop below 13.8!

• Answer:

  Hello, Thanks for the follow up. Makes you wonder if you ever needed an alternator and also why no one questioned the ecm, battery and ip unit as to what burned all this stuff out. I did not figure on the ground relocation because you stated all the wires were checked. Glad it worked out for you though, You finally found someone competent. http://www.autotheftexpert.com