20 Most Recent 1989 Porsche 928 Questions & Answers

it is problem with any control module , go to workshop ,let them scan it , then they will replace faulty unit, it could be instrument cluster or body computer module.

They are relay 17(XV11) fuse 22 numbers from left to right

if you have a part number you may be able to get it from audi or vw as they own porsche

chck out this site, it has free diagrams etc in pdf format:-
http://www.onlinefreeebooks.net/automotive-machinery-power-equipment-ebooks/porsche/wiring-diagram-porsche-type-928-s-model-89-pdf.html

Your problem can also be with the Bosch ECU, these are prone to failing and also control the fuel pump, they can however be rebuilt.

Please list these issues with the comment link below and I'll see if I can help.

Porsche 928 Wikipedia

There are two relays in the fuse panel under the front of the passenger footwell mat...board...also there are fuses for the headlamp motors there as well....there should also be a key indicating which fuse is which. And which relay is responsible for headlamp motor operation...I think it is the large on all the way to the right....wiggle while you have the headlamps turned to ON position...see if they pop up.....let me know how it goes...The headlamp relay is problematic on that model.

Have you checked all the wiring around the clutch lever, sounds like it shorting a wire out or making a connection somewhere.

Find the Porsche dealer service centre / parts department as they will have replacement keys and probably a key cutting and programming machine.

It definitely sounds like the motor. You need to disasemble the seat to get to the mounting bolts to remove the seat and get to the motor. Might be easier to just fix the handle and move the seat manually.

could be low on transmission fluid.

its located under the fuel tank cover right rear