Voltage problems, dealership couldnt figure it out

[Robafb]

I swapped in my new engine last month and ever since I have been have voltage problems. I cant turn on defrost, heat or A/C without the voltage gauge reading around 8 volts, it will run that way but the car cuts out on occasion like that. With everything turned off except for radio, voltage stays around 13 or slightly below. I took it to the dealer but there excuse was a bad gauge which isnt true. Can anyone HELP?

[mcjoslyn]

Find another dealer.

From the sounds of it, you either have a dead cell in your battery, or your alternator is weak (or both). I would check the battery first, but even with a dead cell, I wouldn't expect such a big voltage drop (I'm assuming all this is at idle) when you tax the system. Go to Autozone or someplace like that and they can do a load test for you.

[PiLOTLiTE]

I've had voltage problems too after my engine swap, althought not as bad as yours. My gauge reads slightly below the 13 most of the time and a little lower with A/C, lights, or rear defroster on. I have yet to find the cause and have very few theories.

1. Bad ground
2. Voltage regulator differing between model years (I went from a 98 motor to a 2001 motor)

[need4speed]

I think there may be a bad ground or a short somewhere, maybe some wires connected in the wrong spot? Examine your wiring first, maybe try different things to isolate the problem if you can.

[FirebirdGT]

How about that the alternators are different for different years?

95-97 10464075

98 10404418

99 10464409

00-03 10464437

[ July 03, 2003: Message edited by: FirebirdGT ]</p>

[PiLOTLiTE]

<blockquote>quote:</font><hr>Originally posted by FirebirdGT:
How about that the alternators are different for different years?

95-97 10464075

98 10404418

99 10464409

00-03 10464437

[ July 03, 2003: Message edited by: FirebirdGT ]<hr></blockquote>

I wish it was that simple. I tried my '98 alternator and the '01 and got the same result.

[Salvader]

hi, when the problem ocurs, measure at the batery with a voltmeter, it should read from 13 to 14.9 volts, if it reads ok then measure at the bat terminal at the fuses compartment. I had the same problem and it only was some bad cables that gets voltage to the instrument cluster.

[jamie]

where is the voltage regulator at?

[Robafb]

Thanks for all the help, I found a loose grond leading from the negative battery terminal that connects to the block just above the a/c compressor.The block was painted over there also.Sanded down a shiny spot and retightened, car runs and works great.