starter wiring

[Christien]

I pulled the starter today to clean up the electrical connections because of an intermittent no-start problem. I was dumb and didn't pay much attention to the wires I was disconnecting (I'm usually pretty good about that) and when I went to put it back together, had to refer to pictures here on Pelican.

So I've got an extra wire that looks like it should connect to the post on the solenoid that connects to the starter, but for the life of me I can't get it to reach. I've mangled it pretty badly, but it's easy to bend back into shape. The thing is, the car starts fine. I tested it, and it started on 4 out of 4 tries. And what's also weird is that in reading here and on clark's garage, I only came across mention of 2 wires, the wire to the battery and that to the ignition, but I clearly have 3 wires coming out of the same sheath.

Here's a pic. Can anyone offer any explanation?

Thanks!
Chris

[Christien]

Ok, a bit more info I forgot. When I start the car and it idles, the battery light comes on and stays on. I'm not too familiar with 944 electricals, but if it's at all similar to my 911, I'm guessing this means I'm running off battery power, and not the alternator. Is that right?

[2Tight]

Originally Posted by Christien

Ok, a bit more info I forgot. When I start the car and it idles, the battery light comes on and stays on. I'm not too familiar with 944 electricals, but if it's at all similar to my 911, I'm guessing this means I'm running off battery power, and not the alternator. Is that right?

That wire goes to the alternator and attaches to the large lug from the battery positive. Many people just run a separate wire from the battery positive directly to the alternator and cut that wire off. that avoids many problems and simplifies the charging circuit. You really should replace those cables once you see the green corrosion product; that means that the wire is corroding under the insulation and adds significant resistance to the staring circuit. Good wiring was never a Porsche strong point.

[Christien]

Can you just clarify what you mean by the large lug? Is that the same post that the thick copper end is already attached to? (top post in my pic above)

Thanks!

[jwade944]

Both large wires connect to the large lug where you have the corroded wire now. Make sure the ground on the bellhousing and on the rear of the engine are cleaned. Often, the problem with a starter is a poor ground.

[Christien]

Ok, got it started right with no battery light - thanks for clarifying. I'm still having the intermittent start problem, but it seems a bit better, maybe 6-7/10 now, whereas before it was 3-4, except when sitting for more than a few hours, when it was 10/10. So that leads me to believe that it is indeed a grounding issue, as I seem to be improving current flow. I cleaned the ground at the back of the engine, where it attaches to the firewall, but how the hell do you access the other end of that strap, on the engine itself? I can see it easily enough, but I can't figure out how to get a wrench or socket down there!

Thanks for your help!

[2Tight]

Originally Posted by Christien

Ok, got it started right with no battery light - thanks for clarifying. I'm still having the intermittent start problem, but it seems a bit better, maybe 6-7/10 now, whereas before it was 3-4, except when sitting for more than a few hours, when it was 10/10. So that leads me to believe that it is indeed a grounding issue, as I seem to be improving current flow. I cleaned the ground at the back of the engine, where it attaches to the firewall, but how the hell do you access the other end of that strap, on the engine itself? I can see it easily enough, but I can't figure out how to get a wrench or socket down there!

Thanks for your help!

I abandoned that bellhousing ground completely and ran my own with #2 wire directly from a grounding block at the battery to one of the starter mounting bolts. It eliminates most of the high contact resistance problems that can build up at dirty grounds. I can't emphasis enough about getting rid of that corroded starter cable; you can't imagine how much voltage drop can take place across a corroded cable like that.