I've been having a charging problem in my car (95 formula) for 2 plus years now I've change every thing I can think of and it's still there so I bought a 200 amp alternator thinking that would fix the problem but no luck now when I'm at a light the volt gauge drops down to 9-10 volts PLEASE HELP I'm ready to shoot my dam car a put it out of it's misery

 

Battery cables have been replaced with a heavy duty set also?

 

Have you tried using a voltmeter to see if the gauge isnt reading right? Clean all the grounds?

 

I have changed the battery cables but with stock replacement were do i get a heavy duty set at????

 

If you're using the voltmeter in the IP, that's your problem. Those things aren't accurate in the least. Second, if your system was actually down that low, the lights would dim and crazy things would start to happen with the PCM. Does it?

Last, as Turbo mentioned, have you checked the voltage across the battery with a voltmeter while the engine is running? If the entire battery/charging system were ok, the voltage across the battery would be around 14 volts.

 

the lights go dim when it drops down the voltage is 10-12 volts

 

Ok. So list the things you checked and the results so we can see what you missed and tell you what it is.

 

ok here we go
New Battery (optima red top)
200 amp Alt.
2/0 Positive, Negative, and engine ground cables
New Gauge cluster
I did a parasitic drain for 3 hours and saw nothing
I checked voltage across the battery and read 14.6 volts in Park and 12.2 volts in Drive could it be that my fuel pump harness is bad (200,000 miles) or is my PCM on it's way out ?

Also what sends the signal to the voltmeter on the dash ???

 

there should be a mini volage regulator in the dash cluster. It adjusts the voltage that the gauge sees.

Have you ever taken the belt off and see if you could spin the damper by hand. My damper would do that. I always thought I had a belt slipping due to the noise. Then I got smart! If you damper is spinning and your alt isn't turning at the right speed at idle. Then, the alt would not put out the right volts.

 

i'm guessing that the mini voltage regulator is fine since i changed the cluster

and I can turn the dampner but not maybe 1/8 of a turn if that

 

Ttt

 

Any Idea's ???

 

paint a line cross the damper hub and then start the car run it for a few minites. If the line is still lined up damper is good.

 

I don't think it's the damper when I put in the 200 amp Alt. I had to go to a smaller belt . Does anybody know were all the grounds are in the Engine bay

I've changed/Cleaned the following so far
New Neg. Battery Cable
New Pos. Battery Cable
New Engine / Frame ground (the one on hat bolts to the drivers side head)
Cleaned the power block next to the battery and the ground lug above it
I read there is a ground by the radiator is this true ?

 

I had a funky intermittent power/voltage issue that was caused by a bad connection at the ignition switch. Might want to check that out as well.