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Ok, it will go in tommorow to be tested. But we have tried 3 alternators and 2 batteries. The shop that fixed it is scratching their head about it. What else could possible cause this problem? It seems like the battery is fine, and the alternator is fine, yet it is not charging the battery. Would at bad regualtor cause this problem? Thanks again for all your help and quick responces!
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1991 Pontiac Firefly, 1.0 ltr 3 Cylinder. About a month ago the car would not start. I replaced the battery and everything seemed fine. After a day or two the lights got weak and the engine had little or no power, after shutting the car off it wouldnt start again. Replaced the battery and the same thing happened. Took the car to a mechanic, who replaced the alternator with a used one. It ran fine for a few days then the problem returned. We took it back to him and he replaced the used alternator with a rebuilt one. Fine for a few days, then it happened again. He then replaced it with another rebuilt alternator and a new battery. Worked for about a week, then last night it started losing power, lights were weak, stereo wouldnt work. Today the car wont start ( Just clicks ).( It will start with a boost, but once the cables are disconnected the engine runs weak and lights/accesories barely work) It seems to me that it is an electrical problem but it is obvioulsly not the alternator or battery. Any Ideas? Thanks for your help.
Answer -
You stated: "It will start with a boost, but once the
cables are disconnected the engine runs weak
and lights/accesories barely work)
QUESTION: Are you disconnecting the battery cable(s) while the engine is RUNNING ?.
Sorry, I meant that once you disconnect the booster cables, not the battery cable. As a side note I did try to disconnect the battery while the car was running and it kept running. ( Most cars with a dead alternator will die when the battery is disconnected right? ) Thanks again, Bruce
autohelp
Answer -
NEVER EVER disconnect the battery when th engine is running especially on a COMPUTERIZED car that has a COMPUTER of which yours HAS.
Most vehicles alternators are controlled by the computer and disconnecting the battery with the engine running usually results in destroying the voltage regulator in the alternator and or the alternator control circuit in the COMPUTER.
Take the alternator OFF the vehicle and take it into any larger auto parts store and they will usually test it for FREE.
IF your EXTREMLY LUCKY you may NOT have DESTROYED the vehicles COMPUTER.
Let me know how the alternator tests out.
autohelp
Answera bad regulator of which I believe is within the alternator, a shorted internal computer or excessive draw on the battery such as a light being left ON in the trunk or a SHORTED circuit.
Normal battery drw is .50 amps or 1/2 amp. Anything OVER ONE AMP draw or more from the battery sitting over night will drain the battery.
What mechanical work or ANY kind of work has been performed on the vehicle recently ?. As most problems that occur after a recent repair was made can be traced back to the area of where the repair was made as a wire connection was left loose or something was replaced to cause a short circuit thus causing excessive amperage draw of over ONE AMP from the battery. Look around in the area where work was performed.
Have your electrical system tested for excessive AMPERAGE DRAW.
autohelp
