I just recently bought an 89 740 Turbo that needs a few hopefully minor repairs. The main thing I'm concerned about is the sunroof motor assembly. The power sunroof will open with the switch, but I have to close it manually with a screwdriver. Is it the switch that needs to be replaced or is it the motor assembly itself?

I was also wondering that if it was the motor assembly that needed to be replaced, if I could replace it with a manual assembly which costs a hell of a lot less.

Any answers or info will be much appreciated.

 

The sunroof switch is a known weak point. Start by cleaning or replacing it.

Instructions here

http://www.brickboard.com/FAQ/700-90...gSunroofSwitch

Once disassembled you will find that there are two sets of rotating rocker contacts inside. Small pitted areas will be evident on a few of them.

I used 1500 grit sandpaper to clean the contacts and applied the smallest amount of conductive grease before reassembly. Mine works fine now.

 

I agree clean the switch first.

 

Thanks for the info.