I have recently replaced my daughters alternator on her 2001 Cavalier. Since replacing the alternator the voltage gauge jumps up and down, settles for awhile then does it again. The check engine light has also been intermittent. When the battery died we did disconnect it until the next day when we picked up a replacement alternator. Any info would be appreciated.
If you have an analog voltmeter, measure the battery voltage at the terminals and see if it is varying. If it isn’t go back the chain of connections until you find the variation, i.e. clamp(s), terminals, alternator terminals, grounds etc. I suspect you have a poor connection somewhere.
The ECM will set a code if its supply voltage is varying. It has a hard time calculating how long to pulse the fuel injectors if it is unsure of the voltage the injector will be fed. Thus, clearing up the voltage problem may clear that code setting. You might pull the code to see what the ECM is objecting to.
Hope this helps.
Hi researcher. I apologize for the post that is too late. Just want to ask some things to you. Hope you’re still here. It just happened that my chevrolet cavalier 2004 has a problem with the exhaust manifold. the mechanic says it requires replacement. any suggestions where can i find Chevrolet Cavalier repair shops in our place? please include the details as well. thank you!