Hi guys,

I'm having problems with my '92 964. After the car refused to start the first thing I checked was the DME relay. I manually bridged terminals 30, 87 & 87b the car started without any problems.

Resoldering the old relay didn't help so I ordered a new one. Unfortunately this did not solve the issue.

I tried to narrow down the problem but now I am at a point where I’m not sure how to continue. The problem seems to be that terminal 86 gets no power. With the ignition off I measure a correct ~0 V. With ignition on I get ~5 V instead of the expected ~12 V.

I do have the wiring diagrams for my car but I can’t find out where terminal 86 is supposed to go.

I would appreciate any help.

cheers,
Andy

 

Battery condition?

 

Battery is fully charged.

 

If you are only getting 5V at terminal 86 then I would suspect the ignition switch is going bad.

 

My problem was the crank position sensor.

 

That sounds viable. Do you have any idea how I can check this before buying a new switch? Does the 86 contact on the terminal go directly to the ignition switch?

I guess I can rule that out because my car starts without problems when I bridge the power supply to the fuel pump (DME Relay). Please correct me if I’m wrong.

 

Hi - I think I got it figuered out. Of course it was my own fault . I forgot that I removed the airbag ECU and it seems that the DME Relay is routet through it.

There is a special Bridge Adapter (928.612.220.00) which shortcuts pin 3 and 4 on the Airbag ECU.

Thanks for your help, anyways!