Hey Guys, New to the forum and need some help , Just to give you some background I purchased a 1991 MB 300ce 24v as my 1st car in late June of 2013. The car was $600 with 172k miles. Over the summer i restored the vehicle to almost like new, (Literately everything down to the seatbelt presenter was rebuilt by me) this car had the classic ASR wiring issue which I have now straightened out so the car is (to my knowledge 100% Mechanically good and 99.99% Electrically Sorted). The previous owner was a classic car auctioneer and accidentally purchased this car (no idea how). He had no idea how to work on cars (as he only handles the business side of things) and realized the amount of work needed to get this car straight wasn't worth it to him. he did say this car's electronics were terrible, i managed to fix just about everything down to this last bug. I noticed that when i locked the car using the key, while the key was turned to lock or unlock (both for driver door lock and trunk lock) the Driver side rear window would start to roll down. This model has the "convenience feature" i think its called, when i turn the key to unlock all the windows come down and sun roof opens fine. When the key is held in the lock position on the door all windows go up and sunroof closes except the Driver side rear one which goes down no matter if i lock/unlock. I have no idea and am completely stumped on where to start to check for the problem, im very well electrically and mechanically inclined however any Guidance or suggestions would be extremely helpful. For now (as i live in Rochester. ny and it is -3 out) i just pulled the fuse for the back windows but i want to fix this problem as im one to want everything to work -_-.


-Thanks

 

A possibly easy solution would be to source the wire for the other rear window and splice into it so that both rear windows received the same signal from the car. I am not electronically inclined in the slightest - so I have no idea how to identify said wire, but I think it would work.

Congrats on the kick-*** purchase man! I would love an M104 with non-eco wiring!!

 

Thanks for the reply, Wont Splicing the left and right side together cause both windows to be controlled with one switch at the console? And Thanks! This one did have the Eco-Crap wiring but i painstakingly replaced each wire one by one with same color code.

 

Like I said, no electronic experience :P

I assumed there was a separate signal wire for the key-lock function you were talking about. If not, then I guess it's possible you messed something up in the redoing of the wiring :/ Like crossed polarities, or some such.

But again this is just hypothesizing - I am not an expert in any way, shape, or form.

 

Sometimes trying to figure out the smallest issues like these are the most difficult! Good luck to you buddy! keep us posted if you figure it out.

-Sasa

 

hahaha alright thanks, im sure it wasnt my fault on the wiring because the car came to me with the window issue but since the car had the asr light on, and barely ran i didnt focus on the problem until i had the car up and running, Ill try to tear the back panal out again today and see what i can come up with, Ill keep you posted

 

Have you tried to measure the + and - values on the door messing up, and compared it to the working door?


See what values you get when you turn the key and see if there is any difference between the two doors.. It might put you on the right track to source the fault.

 

First bell that rings in my head is broken wiring inside the tube by the door hinge, it might be shortcutting right there.. Just a longshot but might be worth checking into.

 

Did you ever get this window issue solved? Same thing just started happening to me but only when I "lock" the door. The window is supposed to go up if the key is held in the "lock" position of either the driver's door or the trunk. It's not supposed to go down at all when locking or unlocking the door unlike my 2009 C300 which can do it either way as a true convenience.

Previously when I would open the trunk after unlocking it at the trunk the alarm wound go off. I finally just disabled the alarm by pulling the module under the carpet in the passenger footwell. These electrical issues aren't fun or easy.