I just picked up this car last week (‘86 944 turbo) and have been going through each of the ground connections. I already solved two issues from cleaning up the ones under the driver side dash (hood light and buzzer).

The hardest are the two right next to each other on the bell housing. You really can’t even see them unless you know exactly where to look.

I tried for over an hour without removing the heater control valve and that was a mistake. I jacked up the back of the car about 6” and just a dribble of coolant came out when I removed the hose.

Here’s a pic. If you get these done, the rest are easy.

 

Thanks. Been thinking about doing this as part of my planned preventative maintenance while working to get my car back on the road after a long slumber! How exactly are you cleaning them up? Terminal cleaner and a wire brush?

 

Do your self a favor...
Eliminate the ground point bolts and replace with studs & nuts.
Find the factory part number for the top bell housing plug
Get some heater hose and relocate the heater valve a few inches over toward the passergers side footwell.

 

I just used a cordless dremel with a brass brush for the cleanup and then dielectric grease for install.

That’s a great idea on the stud vs bolt. If it wasn’t all back together I would have done that. Yes, I saw that plug was missing.

Bob