1998 Chevy Cavalier charging system not charging

  • 4 CYL
  • FWD
  • 114,000 MILES
I have been having intermittant charging system problems with this car for a couple of years. I have replaced the alternator 3 times and the battery twice. My assumption is that the battery went bad due to the alternator not charging or vice versa. I now have replaced the battery (tested bad) two weeks ago and the alternator (tested good but under warranty and convinced the parts store to replace it anyway) today. The alternator is not charging. I have put a dvom on the battery while the engine is running and it only shows battery voltage. I also put it directly between the post on the back of the alternator and the negative battery terminal and got the same results. Both connectors are tight. My assumption is that the computer controls the alternator and tells it when to charge and when not to throught the two wires on the 4 pin connector. If I am correct and the computer is just not telling the system to charge, can I wire in a manual switch to manually do what the computer is supposed to do automatically? If I am way off then can you tell me what else to check? This is the only car that my family of 5 has to drive and we are stuck. I am mechanically inclined and was ASE certified in Automatic Transmissions and Steering and Suspension but am week on troublshooting beyond obvious things as I lack experience in that area. I have the ability to perform any check or modification you suggest. Please help. Thank you.
Do you
have the same problem?
Saturday, May 24th, 2008 AT 6:56 PM

1 Reply

Can I wire in a manual switch to manually do what the computer is supposed to do automatically? If you do- you will bypass the field generation control which is built into the PCM-its like not having a voltage regulator to control the alternator output-therfore it will ruin your battery by overcharging it. Also see below


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Sunday, May 25th, 2008 AT 5:10 AM

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