alternator charges it is a 105 amp alt and charges to 120. but the alt will not charge when its in the car. the main single wire has 12v coming from the battery and the heavy red in the two wire plug also has 12v, but the brow wire has no voltage at all. but the gauge on the dash does work. but the alt still does not charge. any help is needed

 

also does anyone know of a wiring diagram for the alt for the brown wire

 

help??? anyone

 

 

The wiring diagram can be found in the Haynes Manual that you can get from any Auto parts store for around 20 bucks which I would highly recomend for any thirdgen owner.

 

The wiring diagram for my 91 Z28 shows the alternator/generator brown wire is fed from a branch circuit supplied by the 20A "FAN" fuse and should be hot in the RUN position. I'd probably start there...

 

Hello
I have a 1991 Z28 v8 5.0 camaro

I am having a issue in this department also.
New Battery holds a charge of 12.6 volts but drains when car is running.
New Alternator just bought and installed yesterday.

Only a two wire plug to the alternator 12v+ on both the red and black wire.
On the red wire that is to the bolt on the back side of the alternator I only get 6 to 7v ? Running I only showed 3.8v on this bolt.

I have checked all fuses my 20a fan fuse shows 11.6 volts with key in on position.

Now my Fan doesn't run when I start my engine its 30 degrees outside so not sure if this is due to the temp or not at this time. Does the charging system in a 1991 z28 run with the radiator cooling fan ? Some where I saw a link that had a charge system relay any ideas on where this might be ? I currently cant find my manual and cant find solid info on relay locations for my car. Any help would be greatly appreciated.



***** Update****
So I made it to page 22 of the electrical forum and found a few things to try and once I began running wires I found my problem !!!! Corroded wire only conducting half voltage. got them spliced together and boom running great. Thanks for all the information on this forum really appreciate people sharing their problems and SOLUTIONS.