Please explain or link, how can I test?
As I understand it, right after starting, there's supposed to be 12v going to the alternator, so that it will start doing it's job.
I think it comes from under the dash.
I think it's the red wire of the 2-wire connector.
If any of this is wrong, please correct me.
Can I just make a jumper wire from that red wire to the bigger red wire by itself?
This alt was working until I used the headlights, then 2 miles on, I hit a small pothole and the dash lights came on, and I noticed the gauge reading 12v instead of 14v. It has not been above 12v ever since, and it's been getting harder to start, until this morning I changed it for another alt I had, then at the gas station it needed a jump.

 

Really? Noone has ANY idea?

 

its happening to me too. can you put up a picture of the wires coming from the dash? my alternator has a wire coming from the battery, i think its not supposed to be there but i jiggle it & it starts

 

I'm still learning hot to use my cellphone's camera, since my Sony died.
Tomorrow morning I'm taking 2 alternators for testing, and I built my jumper wire to try if either alt tests good. I put a blade-style fuse holder in the middle of my jumper wire, so I can try fuses from 5 amp to 40 amp.

 

I had a bad alt, and it still tested good, But I had changed the the battery and bought the best. So I knew it was not the Bat. Did some research and found that the diodes, brushes,and holders,triode inside the alt can be bad and still test ok.And if its a delco can be rebuilt. But if it a after market alt, buy a new one not rebuilt. They run same cost, after core charge. And have a life time warranty

 

I have a bunch of wires going to my alternator , can someone please put up a picture of what it's supposed to look like?

 

I'm pretty sure how mine is connected is wrong because it's held together by electric tape haha

 

I got my issues figured out enough to get me by for now. All of my alternators are used leftovers from past projects. But being on my fifth and final, and being fed up with changing them out, I tried some other ideas. All it took was swapping the 2 wires on the side connector. Surprising. Anyway, here's hoping I don't hurt anything.

 

If the battery doesn't charge while the motor runs, what might the reason be?

 

If the brushes or diodes are bad will it still start?

 

It can but will eventually die. You can charge the battery a few times or more. Sooner or later you will have to replace the Alt. Not only that will put strain on the way the car runs.

 

92RS I will get some picture's for you tomorrow if you want. There are only two main wires, the ground on back. and the connector that has a few wires on it, that is how mine is.

 

The big post on the back is not ground. The little black wire in the 2-wire connector is a ground, and the case itself grounds through the brackets. The big post on the back is the main output. Hot, not ground.

 

Alright thanks. I think that maybe it's my alternator that's bad then because I need to get the car jumpstarted almost every other day haha. & I have an extra wire (I think ground) taped to one of the two normal wires. It's hard to explain but I don't know how to upload a picture

 

no wires in the alt connector are grounds. the alt grounds itself through the case and the case ONLY.

 

the alt is a generator, when turned it produces around 14v to the bat. and to suppy all the rest of the car. noticed you have 12v with the car running. this sounds like your alt is not functioning and just draining your battery.

 

it could be a bad alt, or could just not be hooked up right. there should be a brown wire on the pigtail, that needs 12v from a switched source for the alt to function.