Replacing alternator

[heimue]

Ok, this here is not for my Manta, but for the Kadett project. The alternator I had on the 16V wasn't charging, and I found a replacement from a 1990 Pontiac LeMans GSE. The engine type is very similar, and the new alternator fits the original bracket - so far, so good.
I also bought a jack with some wires, fitting to the alternator (see pic), with a 4 sqmm red wire, and two 0.75 sqmm wires, one black and one brown. I went to "Newnan Auto Electric" ("We specialize in starters and alternators") to check with them where those wires go. You might already have guessed it - the head mechanic didn't have a clue. They specialize in replacing stuff, but apparently that's it.
Now here's the key question: who here can help me out? Anybody has a GM product with the same wires coming from the alternator?

Dieter

[opelspyder]

I'm not sure myself, but if you go to the wiring 101 section at painlesswiring, it shows different alternators and the wiring for those applications, may not show for that one though
Keith

[sawdust]

Could try a pontiac website and look up a 1990 Pontiac LeMans GSE altenator wireing schematic.

might work...

[namba209]

Dieter, this is just off the top of my head, looking at my Chilton's 82-93 GM pickup manual, and I only have a GT schematic to go by as far as Opels are concerned. There should be an insulated terminal on the body of the alternator for the current output to the battery. The Red wire "should" go to the ammeter lite or the alternator lite, and the other two wires not used. At least this is what I'm deciphering from the book I have. On Willit?, with a 95 alternator, there is a 4-pin connector that plugs in to the alternator, but only one wire in the connector. HTH.

[heimue]

With a little testing I found out the following:

- the big red one is not used. It never had any voltage other than between -0.6 ... +0.4V to ground.
- the brown one goes to the charging light, from there it goes to +12V.
- the black one goes to ground, but since the housing is grounded it worked without.

Thank y'all!

Dieter

[guyopel]

Dieter , This is the same wiring connector for the 105 amp alt. that I use on my GT and I have any info. you may need for this setup .
John

[heimue]

Originally Posted by heimue With a little testing I found out the following: ... - the brown one goes to the charging light, from there it goes to +12V.

With a little more testing, I found out that this one need to be connected, or the alternator will not charge! That means, if the charging light bulb burns out, your alternator stops charging!
I assume that is the same with the 105A alternator used on the CIH alternator conversions.

Dieter

[guyopel]

The wire to the charging light is what is used to turn on the alt. and the large red wire is connected to the pos. terminal on the alt. HTH
John

[namba209]

Originally Posted by heimue I assume that is the same with the 105A alternator used on the CIH alternator conversions. Dieter

Actually Dieter, it's the same with the original alternator too. If you were to check both sides of the lite with the engine running, you would see system voltage on each side of the bulb. When there is a difference in voltage on either side of the bulb, the voltage regulator will either increase or decrease output from the alternator, which can be seen on the ammeter. With the engine not running there is only voltage on one side of the bulb and that's what makes glow. You are correct, it the bulb burns out the charging system will not work.