I just bought this truck and cleaned up the wiring nightmare from the previous owner attempt at stereo installation. Being careful not to remove any stock wiring but afterword it stop charging.
The charge light comes on, I replaced alternator, "6 blade" regulater and checked fusible links by the battery etc..
Checked all the wires and fuses.

I read in the manual the discharge light has a relay under the dash.
I removed all the gauges and still can't find it, all I found was the buzzer.

Any ideas would be greatly appreciated and a REAL wiring diagram unlike Chilton with B&W stick style pics with no wire color ID. would be helpful in troubleshooting this and the location of charge light relay.

I check volts from white power wire back of ALT and it reads 13.8v,
when I jump the wire straight to the pos battery it reads 12v?

Check neg battery to alt housing and pos battery to white wire back of alt and got 1 or 2 volt readings on each if not lower.
Both test above done with VR plugged and unplugged.

Thanks in advance,
Mark raininforest at aol

 

Probably a red herring, but...Any chance battery is bad (shorted internally)? If you disconnect posts and charge it with a charger, does it hold charge? Normally, you should see 13.5 volts at the battery when running say 1500 rpm

 

^^ He's right.

if you're getting more than 13.5 at idle with normal vehicle load (electronics) your charge light should not be on and everything should run as expected.

That significant a drop when connected to the battery is very likely a shorted cell.

That being said your post was a bit hard to understand; (not that I mean to slam your grammar) so we may be misunderstanding what you're trying to say. The only other thing I can think of that would possibly apply here is maybe your alternator fuse might have blown; you might want to check it.

 

Hi,
the battery is ok,
I have been using 2 batteries, 1 at a time of coarse while the other charges.
Both batteries are good.
All fuses are good too.

 

UPDATE,
a fried told me the stereo has to wired in to complete the circuit.
I told him he was crazy.
So I wired it back in just like it was, blue wire coming out of trucks wiring harness plug behind the stereo to the red and yellow wire out of the non factory stereo.

It did something because now when idling the charge light is bright red like it has been but when I rev the motor up the charge light goes dim but it still lit.
I let it idle charge light goes bright, rev up the engine and it goes dim.
WTF ??????????

 

NEED WIRING DIAGRAM CHARGING SYSTEM.
On a 79 p/u 4x4 with ex regulator.
I need to know the colors of the wires from ALT.
to VR, CHARGE LIGHT RELAY, IGN. to STARTER and BAT. etc..
Still troubleshooting my charging system.
Thanks

 

Save your self lot of time and headake. Do a gm one wire swap.

 

Hi,
can u tell me how.
thanks

 

http://www.lceperformance.com/Altern...-p/1080055.htm

However, I mounted my GM alternator into the empty smog pump bracket, on my 20r.

 

search, there are many wrightups . i did it on my 80 20r and loved it. put it where the smog pump was and left the oe alt still there so i could use it as a backup if the gm one went bad.

 

check out mt build thread on P4x4. I did the one wire swap super easy.
http://www.pirate4x4.com/forum/showthread.php?t=1056337