Archived Electrical - - In Ogden, Ut

[R C Cola]

Also posted on first gen. Lites brite and dim. Bench tested all componants all

OK 17V at the batt running. somehow gets past the regulator. What--Up

R C

 

[B.G. Smith]

I believe your alternator output is controlled by the PCM. I have an 89 Ram gas rig and it is. I have read where some of the guys have converted to external regulator when this happens. Look at the back of the alternator and disconnect one of the small wire, might be dark blue and dark green, that should stop the alternator output. bg

 

[R C Cola]

Electrical ? ?

Thanks -- I do have a external voltage regulator mounted on the firewall.

Does the PCM still override the regulator ? If I stop the alternator output, then the batt will not charge when it needs to ? I would truly like to not need the

PCM ! Gives me something to try and check out. Thanks RC

 

[B.G. Smith]

Sorry for the delay, I didn't stay up that late last night. If you have external regulator then it is most likely the problem although it could be a bad ground or connection somewhere in the wires to the regulator. The regulator has to see the battery voltage to regulate it correctly. I did encounter a problem once where some of the copper on the alternator where the brushes run came loose and shorted one brush causing the alternator to go wide open. If the regulator checked good on the bench??? then I would check the ground continuity from where the regulator is mounted to the engine and also any wires going to the regulator and alternator. bg

 

[R C Cola]

Solution

Thanks to all. Found one fuse that when visually inspected looked fine, but with a test lite no power. Also found 2 grounds in bad condition, corrosion and rust, repaired. Problem solved. Now charging properly at 14. 7v and all is well.

RC Oo.