928mac

This is the way I went

http://www.928motorsports.com/parts/alternators.php

Jakkq

Although the Alternator may be bad, I just realized today that something with the Fuse Relay Board is upsetting the car. I let the car run until it died down, and then shut the car off. I attempt to fire it up again, and it will not start, even after several attempts. So I move over to the Relay Board and wiggle it around a bit, give it a little thump, and then try and fire it up again, and it goes.

I was actually able to do this today, and I drove the car around the neighborhood and power held. A few minutes later I parked it back in my driveway and power began to deplete. The battery is holding good.

Do you guys think I should buy a New Alternator, or stick with the Refurbished one I have here? I love the idea of the 200 Amp posted above, but that is exceeding my budget for just an Alternator.

Landseer

Have you done grounds and CE panel cleaning, new fuses, and polished the relay connectors yet on this?
If not, start there. 14 pin too. Check continuity to ensure the excitor wire is solid.

Then alternator. Depending on prices around you, the 88 Camaro alternator 105A, may be very economical. Or, just a wash. It works, I run them on two 84 cars.

Jakkq

I did do the Relay Board Reconditioning procedure. Relay Board could be dirty again by now.

I took it out again, and I did not have any power loss. Tach sat at about 14. I drove it good down the street and everything. I am going to take it back out though and drive it long enough to see if it begins losing power. Is it possible that the power could be lost by sitting if a Relay or one of the wires is not functioning correctly?

In any case, I'm going to take the panel out again and clean it up, as well as everything else around it and see if I get any improvement.

SeanR

$700.00??????????? I hope you got a BJ at the same time.

Landseer

BJ and the Bear

Jakkq

Okay, I took the car out again and took a risk, going for about a 10 minute drive to the outskirts of town. No problems, seemed to have full power, and drove like the beast it is. I noticed what seemed to be a burning smell after about 5 minutes of driving, coming from the Engine Bay, but the bay is dirty, and I haven't driven it this fast in about a year.

So I don't know what's going on really. It loses power when it sits, but holds when driven. Either way, I'll replace the Alternator, and work with the Fuse Relay Board, and it should definitely show better results.

Dave928S

Early alternators don't handle poor connections very well and often fail because of them ... e.g. bad main earth.
Before you run another alternator check clean and tighten all the vital connections so that you don't chance trashing a new one. Sounds like you need to go through all connections and earths before you think about a new one anyway.

Jakkq

Last thing I used was CRC QD Electronic Contact Cleaner and Stabilant 22. Should I use this product again for cleaning, or is there something better?

dr bob

That stuff is OK for relay socket and fuse connections where you can't physically clean the contact areas. For everything else, disassemble the connections, burnish the contact areas until shiny, reassemble, and then spray whatever protectant you like on the completed and tightened connections.

Inspect all the power cable between the alternator and the battery. Starting at the battery, current flows to the starter, the alternator, and then the jump post in the engine bay. From the jump post, it goes to the CE panel. Later cars have extra primary feeds from the battery directly to individiual ponts in the CE panel. List of possibilites includes power for the fuel pump and injectors, while later (S4+) cars add the electric fans to that list of exra wires at the battery. For all those connections at the battery, Vaseline is my weapon of choice for protecting from corrosion.

neilh

Have you pulled the top cover off the 14 pin connector and looked for burnt wiring? My 81 - a garage queen, owned from new, had NO problems, until i noticed one of the wires going into the 14 pin looked a little dry - turned out just about every wire in that harness is burnt - now i'm about to replace the entire harness with a remake of it!

deptotpr

It's the awesome early VDO quartz clock which continously runs, and drains the machine..

dr bob

I reread the thread from the beginning and think you might want to stop until you can find a good multimeter and someone capable of using it with you. From your posts, you are using the dash meter for diagnosing, and that's not going to work. You call it the tachometer....

With the multimeter, you'll need to be able to follow instructions and suggestions/questions from the folks helping you here, and report back accurately what you find. I don't want to sound rude, but the way this thread is going, you are asking folks here to help you chase your own tail. Electrical troubleshooting demands precise attention and measurement, and the ability to work interactively with the group here. Lots of help available when you are ready.

Jakkq

I took the Fuse Relay Board out, and it appears to have some weather corrosion in several places. Although this corrosion does not seem to dissipate, are the corroded parts therefore possibly bad?

There are a couple of torn rubber tubes, but nothing much else, and no burnt wires. I noticed that the connector labeled "V" (picture above the last) has another piece that was loose (the white connector).

Several pictures located in the link below:

http://porsche928workblog.blogspot.c...lay-board.html

Bill Ball

Those grounds in the 5th pic look badly corroded. if you have corrosion there, all the grounds are suspect. It would be very worthwhile to do Wally's Annual Electrical Maintenance:

https://rennlist.com/forums/2220328-post33.html

http://members.rennlist.com/jerdmann...l.htm#anchor_2


So far, I see no evidence the alternator is bad. You have recorded 14.4 with the engine running.

You keep saying "tachometer 14 then drops to 10". Do you mean the voltmeter?