99 T/A help.
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Teching In
Joined: Apr 2012
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From: Davison MI
99 T/A help. Haven't check to see any codes yet, but I have a 99 trans am, and the voltage gauge bounces like a basketball. My lights flicker, and occasionally i get a backfire pop. Now a while back I had a bad 02 sensor and a friend convinced me to just unplug them and, which I didn't and it ran fine all summer. But recently past month and a half the voltage gauge bounces like crazy. Sometimes it will hold solid right where it should be, but most of the time it will be bouncing from about 13v to 17v. (just on the gauge) I've metered the battery/alternater cable and im getting a constant 14.4ish volts. My batter connections are good. Any other ideas?
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Lots of things going on here.
What O2 sensors did you unplug? Or did you not unplug any of them? The rear ones don't matter, you can unplug them and the engine will still run fine. Front ones are a different story.
You say that only the gauge is bouncing around, and that voltage at the battery cables is 14.4 and steady, but then you mention that your lights flicker - which would suggest varying voltage just like the gauge indicates.
So I'm a bit confused on the details here.
What O2 sensors did you unplug? Or did you not unplug any of them? The rear ones don't matter, you can unplug them and the engine will still run fine. Front ones are a different story.
You say that only the gauge is bouncing around, and that voltage at the battery cables is 14.4 and steady, but then you mention that your lights flicker - which would suggest varying voltage just like the gauge indicates.
So I'm a bit confused on the details here.
This sounds like a voltage regulator problem. It's built into the alternator and will go out. That is the symptoms my Z28 had when it's Alt. Regulator went out. I just replaced the alternator and was good to go.
Your O2 sensors shouldn't have any effect on your voltage.
Your O2 sensors shouldn't have any effect on your voltage.
