1982 528e central locking mechanism/ module

[Luc1an]

Hello all!

since I’ve had my e28, the doors have always been an issue. The passenger door doesn’t have the locking mechanism ( previous owner took it out I suppose… ), both rear doors have windows that roll up extremely slow and the central locking mechanism doesn’t work. I can’t seem to find where it is in the car and if it even had one. If It did have one how would I go about fixing it, or if it doesn’t would adding it be possible? Any help is appreciated. 

[Mike W.]

I'll tackle the easy one first. The slow windows. You need to take off the door panels, the vapor barrier and clean the old, sticky, hardened grease off the track that the windows go up and down on. It's probably more like glue now than grease. Paint thinner might be strong enough, but you might need lacquer thinner. Expect a fight to clean it up. Then regrease, I would use a light, probably a white lithium grease to regrease it.

Central locking. If it's a US car it had it. Unlikely anything got removed, but components fail. Search, IIRC it's up either in the passenger side glove box or kick panel, but search, it's well documented. Seems like there is a fuse/solder link that can fail if it's overused, check that. Now I don't recall seeing any E28s like this, but I know I've seen E23s of a similar vintage with no lock button, and likely no rod going to it, on the front passenger door. Always with a plug in the top of the door panel where the rod/button would go.

[Blue Shadow]

The CLCU is above the right side kick panel speaker. It has a positional switch that will open the contact when the car flips in an accident or someone operates the power locks too many times quickly. Can be resoldered.  This means unplug it before pulling it and plug it in after reinstall. There are two small hexhead screws holding it in place. The symptom of open safety feature is doors unlock after being locked. Same as when the doors are locked with drivers door open. 

other issues:  Mesa Performance…

http://mesaperformance.com/faqs/centlock.html