pjburges

Do you have the electrical diagrams for this car? You can't possibly hope to succeed without them.

Download a copy of the electrical manual here:

http://cannell.co.uk/Manuals.htm

Cleaning the grounds is good advice but it is only the beginning. These cars just seem to be an electrical nightmare especially once water gets inside the car (aka leaky sunroof).

Consider running independent grounds directly back to the battery. I did this from both headlights and the tailights. Also from the central electric ground.

Don't soak anything else in vinegar. Clean contacts with 1000grit sandpaper or emory paper.

Your blinkers must be well grounded or the mechanical relay will not see the right load to click on and off. Make sure the relay is good. Make sure the relay has a good ground. Clean the bulb sockets.

The blower fan has a relay as well. On some models its not on the central electric board - but down near the tunnel inside the car. The radio relay on some models is also located there.

Anywhere there's a plug receptacle - clean the contacts.

Who cares about mirror motors. Those never work on any car. As to the window motors - yes the 924 has manual crank windows and the linkage is a direct swap. The 924 also has a manual sunroof and thats almost a direct swap. Your window motors have a power relay - make sure its grounded and it works - then test to make sure you have power at the motors. Then replace the motors with ones from a junkyard if they are no good.

Good luck!! Its best to learn to live with electrical gremlins in 944/928s!!

cruise98

It has been my experience that the wiring is first class. The problems with electrical systems are usually due to a PO alarm or stereo installation. This car has been modified and it will take time to get it sorted put. You really need the wiring diagrams in order to trace the circuits. It looked like there are some disconnected grounds under the fuse panel. In Bosch world, brown is ground.

pvtskiles

Thanks for the wiring diagram!

This is quite a bit of information to process. From what I am learning is that there doesn't seem to be standard locations for certain grounds and relays. I have a weird box thing that fell out from under the dash when I was cleaning the grounds and I have no clue what it is. Gonna go snap a pic and post it up.

pvtskiles

cruise98

That is not a factory item. On the 944, most of the relays are in the Central Electric board.

pjburges

Yep - I've got no idea what that is - but it doesn't look like 1980's Bosch. Maybe its something to do with an aftermarket radio.

pvtskiles

The manuals are pretty intense. Any advice on finding ground locations? I want to finish cleaning them all before I move on to replacing more relays.

pjburges

Ground locations should be located at the beginning of the 'Electrical' chapter in the book. They have a picture of the car with roman numerals written on it signifying the location of each ground. (ex I II III IV V VI etc)

Also - if you take a look at the pages right before the diagrams it mentions how to interpret all the symbolization in the diagram. If you read closely it basically tells you where all the plugs and connectors are located within the car too.

pvtskiles

Thanks!

mtccl

Get you a battery ground cable about 24 inches long at any auto store and run it from the grounding point next to the left headlight over to the bolt holding the lifting loop on the engine. This extra ground will do wonders for you providing a direct ground path from the engine to the body.

944CS

I have a few of these made already, 944 specific

simxxi

How about a picture of the MP I location on the Apron? Is it under the car or back seat area or hatch area north of the fuel sending unit? Reason why I ask I have no voltage to my fuel pump fuse, I did check the DME relay already and have ohmed out the harness. I do have power on pins 18 and 35, I also do see 12.5 volts for the fuel pump. I do not have any continuity on pin 10 of the harness. everything else is correct as far as continuity, voltages and resistances.