Battery not charging?

[Mechdawg]

Hey all, The voltage at my battery with the engine running is only reading 12.5 volts so Im pretty sure its not charging. I had the alternator tested at autozone and it checked good. So now Im thinking voltage regulator. I did the mod to install a guage panel from an idiot light panel and the brown wire that runs from the old gen light to the voltage regulator gets cut off. So I was wondering if I did that wrong does it need to be connected to something still if so what? I was reading the conversion FAQ about going to an internally regulated alternator but it requires you to jumper the blue and brown wire together but like I said because of the gauge mod my brown wire is cut off by the guage connector. Sorry for the long post but Im stumped thinking I missed somthing.

When doing the panel mod I did run a new wire to the battery block and another one to the main pos feed on the alternator just like it says on GMC pauls never really said what to do with the old brown gen lamp wire though.

Thanks for any help all
Tim

[Americanrider]

Recommend a battery load test and if that checks out look into the FAQ for a thread on finding a Off-key drain.

[truckdude239]

Originally Posted by Americanrider

Recommend a battery load test and if that checks out look into the FAQ for a thread on finding a Off-key drain.

this has nothing to do with it not charging when the truck is running i would be looking for 13.5 volt -15 volts mine runs about 14.5. if the gage is not working right the gage or idiot light tell the voltage reg what to do if its not getting the signal from the gage or idiot light it will not charge

[Mechdawg]

I put a multi meter on the battery while the engine was running and only got 12.5 volts.

[Americanrider]

Your right truckdude, the neighbor kid came by and was talking about his Buick not holding a charge overnight, then I wrote my reply.... can't do 2 things at once.

Ignore what I posted before about off-key drain.

Taking the battery in to Autozone and getting a load test done is free. It would give you another item to rule out while trobleshooting this charging problem. Are the cables tight and clean?

[sneakysnake]

How hard would it be to put the brown wire back and see if it starts working? Then you would know where the problem lies otherwise Id say replace the volt reg.

[powell72]

I agree with sneakysnake, I think that brown wire goes from the regulator to the ignition switch.

[Mechdawg]

I checked it at the voltage regulator and it still gets its 12v ignition feed. The battery is brand new and tested. Ive ruled everything out but the voltage reg so thats next to go. Thanks for all the help everyone.