Charging question? What's this wire?

[SMOKEDYA]

I have a 3G alt. This has never happened but what does this white wire do in the pic? I left my buddies a few weeks ago and got on it.The battery light came on and the battery gauge droped to almost red marks.So lastnight i had to jump the car. Well i did a load test with my load tester on the battery it came out good. I used my volt meter on the battery and the + on the alt. With this white wire connected i get alt:11.62ish and at the battery:11.59ish and the battery light is on and the volts on the stock gauge stays dam near in the red (might as well say in the red) Then when i disconnect the wire i get at the alt:13.99ish and at the battery:13.55ish,plus the battery light goes off and the volt gauge goes up to the middle mark. These readings are all at idel (1000 RPM or so)So what could be the deal? I know when i had this alt in my coupe the battery and volt gauge would only dip down like this if i took this wire OFF when it was connected it was fine. I only know this cause sometimes it would fall of cause it was loose,since it's been on this car i reterminated it and it's been fine till now!? peace

john

 

[MustangLX-5.0]

The white wire is the stator wire. The grey plug goes on the alt, then the other end ties into the white wire from the old power cable (2 orange and one white wire). How do you have this wired up? It has to be connected.

 

[SMOKEDYA]

just like you stated!Untill i got on it that day it's been 100% fine! peace













john

 

[SMOKEDYA]

Is the stater inside the alt? And if so if it's bad would it cause this to happen? peace











john

 

[jrichker]

Old alternator power plug

Rear view of 3G alternator

 

[MustangLX-5.0]

I'd like you to try a test. I have a slight hunch but I want to rule this out. First, the stator is the big round thing inside your alt that has copper wire wrapped in numerous places. This is one of the main components of generating the voltage. The stator is the immobile portion. It is possible that one of the diodes have partially failed alowing current to either work in reverse or generate AC on the output side. Unplug the stator wire, and test your DC voltage while engine is running. Now, remove leads and switch meter over to AC voltage and test. You should NOT get any more than 0.5V AC. If you do, one of the diodes are bad. And that may also be causing your voltage to be locked, but fails when stator is connected.

 

[MustangLX-5.0]

The image jricher posted is exactly how your stator wire should be connected.

 

[SMOKEDYA]

Well this is weird? I took the alt in to get tested. It tested fine,so i bolt it back on and check over the harness and everything looked fine. So i plug it all in and the dam thing is just like it was before this happened! WTF! peace












john