Missing Alternator Wire?
Thread Starter
Instructor
Joined: Jan 2008
Posts: 143
Likes: 1
From: Beaumont TX
Missing Alternator Wire?
The plug circled in the photo below seems to have a wire broken off on its right side. Should there be one? If so, what does it do and what problems will its absence cause? I can't locate a wire that might connect there. HELP! Any expertise will be greatly appreciated.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
It's missing the brown wire- that's the one that excites the field in the alternator when the key is on. Unless someone jumpered the 2 terminals in that plug it's very likely your alternator won't charge.
Looking at theat picture again, I'm wondering what that 2nd insulated terminal on the back of the alternator is. Don't recall ever seeing one like that. It's between the red wire just off the end of that zip tye
Looking at theat picture again, I'm wondering what that 2nd insulated terminal on the back of the alternator is. Don't recall ever seeing one like that. It's between the red wire just off the end of that zip tye
Racer
Joined: Feb 2009
Posts: 427
Likes: 49
From: Pgh. Pa.
That style alt can be correct for 80-82 c3 It is a rebuilt unit and not original. A lot of rebuilders would add the other insulated terminal. It is mostly used on industrial and truck applications. It is an AC tap. (non rectified power from 1 phase of the alt) Without the missing wire at the plug (exciter wire or lite wire) It may or may not charge. If it is charging, it will only start to charge after the engine is reved to increase RPM like a 1 wire type. But most vet owners rev em up any way. I would locate the wire and correct it.
Thread Starter
Instructor
Joined: Jan 2008
Posts: 143
Likes: 1
From: Beaumont TX
Steller: You nailed it! It does charge, but barely and I am going to get it checked today. Also, it does not kick in until I rev it to at least 2000 rpm which is a pain in the butt.
This means I can't let the wife drive it because she will never remember to look at the gauge and the battery will run down. (Maybe I shouldn't fix it after all).
Just kidding. I'll start looking for the brown wire TimAT mentioned.
Thanks to all of you!
This means I can't let the wife drive it because she will never remember to look at the gauge and the battery will run down. (Maybe I shouldn't fix it after all).
Just kidding. I'll start looking for the brown wire TimAT mentioned.
Thanks to all of you!
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Steller: You nailed it! It does charge, but barely and I am going to get it checked today. Also, it does not kick in until I rev it to at least 2000 rpm which is a pain in the butt.
This means I can't let the wife drive it because she will never remember to look at the gauge and the battery will run down. (Maybe I shouldn't fix it after all).
Just kidding. I'll start looking for the brown wire TimAT mentioned.
Thanks to all of you!
This means I can't let the wife drive it because she will never remember to look at the gauge and the battery will run down. (Maybe I shouldn't fix it after all).
Just kidding. I'll start looking for the brown wire TimAT mentioned.
Thanks to all of you!
you have to make sure there is correct resistance....~200 ohms or so in that circuit, or some dash light,
that wire is a double purpose wire, first off, if the engine is still, the red dash idiot light comes on, say no charge to the battery....then it serves to excite the alt charge/output when engine running lo rpm.....you open that circuit and the reg in the alt dunno the thing is supposed to charge, untill you rev engine pretty good....
essentially what you have now is known as a 'marine conversion'....for boats....
Thread Starter
Instructor
Joined: Jan 2008
Posts: 143
Likes: 1
From: Beaumont TX
We solved the problem yesterday. We found the missing brown wire and got a new connector to plug into the alternator. We had the alternator tested at Auto Zone and while it was still charging, its internal voltage regulator was shot. We bolted in a new one and everything works.
Thanks again to those of you who helped me out!
Thanks again to those of you who helped me out!
