I have the electrolux system so dont know if yours has the micro switch. If it does it is attached to the motor . You will need to remove the set up from the car. Not a major job. Do a search as there are lots of helpful posts on this covering all set ups. It cured mine.

 

If it is an untouched 1985 then it has the previous Lucas system, Brinny.

 

I'm going to take another look today and photograph what I have and post it here. Yesterday I looked at the stalk switch, this is what I found.

I'll take a look at the motor later and post