Alternator issues.

[Bass Man]

My batt light stays on and my voltage reads 12v on my voltometer, and my car will die if I take the ground off (I have a carb'd car, so don't worry) BUT! I had my alternator test and it put's out 14.9v, so it is a good alt....

This is a 3 prong plug, and only 2 of the 3 show voltage when the key is on. The motor is grounded, and I know this cuz I blew the 70a fuse on the intake.

Is there any explaination for this?!

On the plug:
The Green/white is hot as well as the Black/yellow, and the blue/white is neutral (not + or -)

[russiankid]

Where does the volt meter read 12 volts?

[Bass Man]

At the ignition switch.

Damn that was fast, lol.

[Bass Man]

It acually may be a ground issue... The battery light turns off if I rev past 3k.

[russiankid]

At the ignition switch.

Damn that was fast, lol.

It should read 12 volts at the switch. What does it read at the battery?

[russiankid]

It acually may be a ground issue... The battery light turns off if I rev past 3k.

Check and make sure all of the grounds are secure, also check to make sure battery clamps are secure and not corroded. Make sure the ground on the thermostat housing and the transmission are connected.

[Bass Man]

I acually do have a ground wire that is not attached to the thermo-housing. Is that a possible cause?? It worked before I took the carb off and adjusted my A/F screw, then I started the car back up and noticed I didn't have alt. juice. I felt the wires down to the alt and they were soaked with gas/coolant.

[russiankid]

I acually do have a ground wire that is not attached to the thermo-housing. Is that a possible cause?? It worked before I took the carb off and adjusted my A/F screw, then I started the car back up and noticed I didn't have alt. juice. I felt the wires down to the alt and they were soaked with gas/coolant.

I'd reconnect the ground and also check to make sure none of the wires got damaged by the gas.

[Bass Man]

Does that sound right, though?? hot on 2 and not on the other?

Got it all back on and started it up. Jumped up to 14v for half a second then back down. Tried wiggling the plug and that did nothing.

I had Shucks check it for me with the alt/start machine. They put a plug on it and put something on the output post and everything seemed to work... I get it home, the alt wire that goes to the battery has power, along with those 2 other wires.

[xxxfrankensteinxxx]

are poower and ground wires stock?

[Bass Man]

Yes they are. They all seem fine to me. This just doesn't make ANY sence at all... It's a good alt, the wire that comes from the alt has 12v...

The ONLY thing I can point at is not a good connection between the plug and the alt, but even that doesn't make sence cuz Shucks pluged theirs right in and it worked.

I had some extra speaker wire with the female connections, so I connected them to where the 2 12v wires were in the plug, and all I got was a little spark (like a "work" spark, not a short spark) and I still only had 12v everywhere.

I one of my voltometers to the battery with the car running... 12V.

I took the battery wire going to the alt to check the output of the alt, and there was none..

To clear some stuff up; the black/yellow wire is ALWAYS on, and the green/white wire comes on with the key on.

[AccordB20A]

brushes in the alternator. had the same problem and if i revved it over 3 the light would go out. that may be the problem

[Bass Man]

I figured it was the brushes before I had shucks test it. I don't know how the hell they get it to read 14.9v, though... That's what's holding me back from taking it out of the car AGAIN. I'm just glad I don't have emmision crap... Cuz I don't need to get under the car to get my alt out anymore :P

[AccordB20A]

maybe it was putting out 14 volts but the brishes are so fucked it cant put out any amps to back up the volts. sort of like powering your car from a 9v battery if you know what im saying.

[Bass Man]

I asked what kind of amperage it was putting out but they said they couldn't tell...

I guess I will rip the alt out agin and disect it. Hopefully it's just the brushes and not my electronics...

[Bass Man]

Man, those brushes are cool! but they aren't wasted... There is about 1/8" left between the contact and the wire.

Acually, I noticed something... The brushes won't "come out" anymore than when I took them off the alt. The brushed need to be in contact with the pole at, right?

[Bass Man]

lol!! YES!! everything it fixed!

It WAS the brushes. $10 at an Alt. repair place... That was a $40 saving just opening up the back of the alt.

Thanks all.