Kacyc3

check the red wire from the alt going into the firewall plug.

ramair_bryan

That's the one of two big reds that have 12v. The second red, I haven't traced yet. I bet it was for a stereo at some point. This afternoon, I'll repair the fuse-able link and test the charging. I may disconnect the second wire to see if any ill effects. (the less the better).
Stay tuned.......
same bat channel...........

Kacyc3

You might want to unbolt the harness from the firewall and check inside the connector too mine had problems and started melting.

ramair_bryan

I'm going to be in that firewall shortly.......
Feeling better, I took the alt down and watched them test it on the machine.
14.2 v. I'll take that.....
Installed it back on the car. Started it up, (had 11.99 v in the batt).
Made 15 v. Cool I thought.
But I can't leave well enough alone.
Tested out put at the 2 wire plug on the side. Top (red wire) nice and bright. Lower wire hardly any lite.
Freaking great.
As an added bonus, It doesn't charge again.
Wiggled all the wires, slammed the door twice, yelled at the neighbors dog and went in the house.
Did I mention all this California rain is leaking right where I'm trying to work?
I need to trace that bottom wire.
More in a min............

TimAT

Pretty common for the brown wire to break right where it goes into the alternator plug.

Antz81

Because the brown wire is supplied through the warning lamp it should be dull when using a test lamp. Thats why i said turn turn the ignition on (without starting the engine) and unplug the connector and ground the brown wire. It should bring the warning lamp on nice and bright.
if the warning lamp is working now then no need to check the brown wire.

ramair_bryan

Ok,

I'm a little slow. Need more amphetamines.....
least my heads not pounding any more from this flu.

Antz81

You did say it stopped charging again. Do you still have 12 on both reds, and the warning light working correctly? How are you measuring the alternator output voltage? And Where?

Big2Bird

On an 81, the output of the alternator goes down low in a loom, and thru the frame, and up via a grommet into the battery compartment. It hits that junction block in there, then jumps to the battery. Check all of this wiring.

ramair_bryan

I know it seems charging the battery shouldn't be that difficult.
I complicate things by feeling not well yet...........
I test voltage using my multi meter set to dc. Red to large POS out. (This is not to be confused with the normal corvette forum terminology we usually use ......)
neg at ground (large ground wire bolt pad).
Then direct to alt body. Then battey terms etc...
I like to just pierce a wire with the ice pick tester and just see how bright.
They make really cool ones now with LED bulb. No burn outs. (Not the burn out that we're , Oh never mind...........
Just started raining again.
Our animals started lining up two by two......

ramair_bryan

success!
Bad wire connector. Big red wire. Sure looked good. seemed tight,
But cut it off and added a new one. And off we went........... Dang glad you guy's helped get me thru this. Still feel like crap, but Went for a ride today. all seems back to normal.
Thanks again.
ramair in calif............