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Your Noble Friend ;-)
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Discussion Starter #1
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
 

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Opel Key Master
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Painless wiring

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
 

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

might work...
 

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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.
 

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Your Noble Friend ;-)
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Discussion Starter #5
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
 

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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
 

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Your Noble Friend ;-)
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Discussion Starter #7
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
 

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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
 

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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.
 

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1970 Opel GT. Looking for some help as I am reaching the point that most everything, excluding the suspension, and fuse box and contents has been replaced/rebuilt, refurbished and I just wish I had done more of that earlier in the restoration process. This forum was not around then so I did not have the benifit of so much wisdom and knowledge as available today. So I am now thinking about two main, very important, overlooked parts , the alternator and starter - age being the motivator, 50 years and best guess 140-150,000 miles, odometer stopped at 100,000 miles, roughly and it seems as a preventive measure, maybe the prudent thing to do is replacement sooner than later. The reason for my post is that I have read, for the past several hours about replacements of both units going back to 2002 and I figure things may have change a little since then. Some of the posted discussions revolved around having to make modifications or not fitting correctly, Those are two things that I don't want to have to deal with as my needs are simple and I am looking for the following.
  • I don't think I need a lot of additional capacity as the only thing I have added is a retro stereo and I have no plans for adding anything else - based on what I have read I look forward to turning the key and getting a quicker response from the starter
  • As mentioned above and his is most important - A direct bolt up with no modifications - a part that fits the way it is supposed to fit and fits like the original - over the years I have made purchases that did not fit or required modifications that I discovered after the fact - simple is better at least for me
  • I have read about three options for the starter - Bosch - Delco - and Kragen - I figure that the cost differental between the three is not that great so that does not factor in to the final decision, last one I will ever buy, that is, if it is as good as the original It scares me when someone says they have replaced the starter 3 time in ten years
  • Same with the alternator - I want to keep it simple and easy. A good reliable component that gets the job done - again like the orignial that has lasted 1/2 century, and 150,000 miles
  • Last consideration - does it make sense to just have them both rebuilt. I have no experience with alternators or starters as I have never had an issue with them. So could a simple rebuild by a certified shop make sense.
Thanks to everyone for their comments and recommendations. Much appreciated.
Best Regards, Carl
 

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Opel Rallier since 1977
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The old Bosch alternator system is quite old and somewhat limited, and uses a very old regulator. So, unless you want 100% period correct, I would suggest that you go with something newer. I have been using the GM 10si units in various version for over 40 years. Not a perfect direct drop in fit, but not too hard to modify things for it, yo can buy them anywhere at anytime, and wiring in to the car is easy.

The stock starters have been working for me fine forever. Not the most powerful, but get the job done, even with higher compression like in the current engines.
 

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The stock starters work fine, so long as they are in good condition. I prefer Bosch, but Delco starters are also good. I have never heard of a "Kragen" starter. The solenoids can actually be the weak spot, but are easily replaced.

And of course, a "starter relay" is essential. The steering column ignition switch contacts are too weak to rely on.

Opel GT Source sells the permanent magnet 2.4 starter, which are MUCH lighter than the stock starter and supposedly much more powerful. But I personally don't think they are that much better than a good stock starter.

The stock 35 amp alternators are a bit weak, but unless you add significant load, they actually work well. Even with an electric rad fan, the 35 amps will suffice. I prefer the 45 and 55 amp stock versions from '74 and '75, as they have a better brush assembly, as well as the added output.

The biggest improvement to a stock alternator is to replace the stock mechanical regulator with an electronic version, which provides a far more stable voltage.

The GM alternators seem to be obvious,
as they don't need an external regulator and are far more powerful. Except the brackets require modification and seem to be prone to failure.
 
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The 2.4 starter is a great upgrade direct bolt in unit. I recommend it highly.
 

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Is it worth it or even possible to just have the old alternator rebuilt. As mentioned previously I really don't want to have to modify anything if at all possible - just want to plug it in and hang it from the original bracket. If not a rebuild is there an alternator out there that is basic and will just plug and play, again looking for easy. I have the electronic voltage regulator with 2500 miles on it so that should be OK. Thanks, Carl
 

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It is absolutely possible to have the alternator rebuilt. Look for a rebuilder in your area.
 

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Great Idea - have purchased around $11,000.00 or so from OGTS over the years over 2,000.00 this year as I got the bug bad this time to go ahead and finish it up, but does that really ever happen, finish that is...I was kind of hoping someone would say yea you can rebuild it yourself for 50 bucks but sometime it best to take the easy way. Thanks for waking me up on this one. Best, Carl
 

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If it only needs bearings you can do it yourself for sure.
 

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I think I might have a used one but it would be in NY. I can have someone look for it if you want me to. You could have it for the cost of shipping + $10.00. It came out of a running car.
 

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If it only needs bearings you can do it yourself for sure.
Actually the problem is it does not appear to charging as well as it should. But while in there I would want to replace what ever could be an issue on a 50 year old piece of equipment.
 
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