Thanks MrMerlin...it would seem that it is most likely the Box..and the only way to see if it fixes the problem is to find another to test..I guess I can start with Ebay or the Rennlist classifieds...I will post the update on the results as soon as I can find another box..
thanks again everyone..
al

 

It would be better if you can find someone near you with a 928 who you can swap with for a test.
As MrMerlin suggests, put yours in a different car and see if the problem follows.

Also, I would stay away from E-Bay.
Try 928 International.

 

928's around here in San Antonio are as rare as hens teeth..I will be checking out the 928 international website..just have to get the correct part number for my 82..just curious, are the boxes compatible or similar?? or unique to the respective year..
thanks again..

 

I got one for a later car off ebay for my 83 euro and it does work. I get a brake pressure warning once or twice that I can cancel. the original brain went totally nuts. so for 50 bucks it's mostly ok. I took the one from my 83 usa car and no warnings. I put the ebay one in my usa car and it did the same thing. warning from the later unit may due to the early style brake system. Did any of that make sense?

 

Fully understood...so besides a clickable warning on different Modules, it will work..as long as its not the permanent caution warning..
Thanks Rcrone..
al

 

Chief. Not an expert by any means, but it worked for me. I'd try to get the correct year if you can. the later unit is smaller in size but the plugs are the same and it still mounts in the dead pedal no trouble.

 

I do not see the warning light for the battery lit in this test. That determines whether the excite wire for the alternator is getting an electrical feed. Maybe this is the problem?

 

Linderpat..isn't it the light right underneath the battery charging gauge that is lit??

thanks

al

 

On mine, it's the battery symbol, but I have a 78, and it's a bit different

 

My car is an 81 - the parts diagram shows the central indicator module 928 641 602 01 to be identical between our cars.

An early issue for me is that I was having "Brake Press" issues that were only cured by replacing the brake master cylinder. Note that a "Brake Press" signal is only cleared by disconnecting the battery. Please try this before doing anything else.

I had other issues with mine when I purchased the car. I did buy one off of e-bay. Be aware that there is a 'reduced functionality' version of this box - I mistakenly purchased one of those also.

I ended up purchasing another unit off of e-bay - it didn't work much better than the one that my car came with. There is a user, sharkskin, who has some excellent writeups on these earlier cars. I used his procedure to refresh the e-bay purchase and it now works correctly.

 

Awesome Information..I think I have the skills to address the module, so hopefully it is a simple fix..I just know that the warning light blaring at me is annoying, when the car used to be okay prior to then..
thanks again...

 

On my 82 there is a broken wire in the sump. I found it last week during sump removal. This wire detects the oil level. Maybe it triggers the alarm system telling you there is a low oil level. You can remove this sender from above.
Another thought; do you have enough thickness left on the front brakes? Just quessing..

 

UPDATE!!

So after testing and checking all wiring and the suggested opinions to replace my CW Module, I had no choice but to purchase another Central Warning module to clear my errors..the original part number that is on my 1982 CW module is -928 641 602.01 and I replaced it with an Ebay one ($69.00) part number -928 641 602 04.
Now everything works as intended. In fact my Fuel reserve and engine oil light are now working as well. I get no errors or erroneous lights. so if your having problems with your central warning systems, and feel that you checked everything, you might want to replace your CW module. See the before and after pictures as it is now.

thanks to all veterans 928 mechanics with your suggestions and opinions.. Now to tackle my HVAC issues
Al

 

Glad to hear you got it fixed.

Thank you for posting a 'finish' to the story. So many folks never bother to post how the situation ends.

 

I agree WJoe...thats why I posted the part numbers that worked for me, in case someone else did a search for this exact problem ..also thanks for your help as well
al