W124 Coupe - various electrical glitches - help!

[grenachenoir]

I have recently purchased a very nice 1991 W124 300CE. It's a cracker engine-wise but has a couple of electrical glitches that I need to sort and hope that someone can help me with.

First, the front passenger window doesnt work at all. I have tried swapping the switch with the working drivers side but that didnt help. I removed the door trim and listened for any noise at the motor - nothing doing. What is the next step before swapping out the motor? Are there relays to check? If so, any idea where they are located - and can I swap with one of the working ones to test out? Can I check voltage at the motor by putting a voltmeter across the two wires going to the motor? What settings should I use and what am I looking for as a pass/fail? (you can probably tell I need my hand held a bit here ) Any other ideas before I go to the trouble of changing the motor and regulator?

Next, the drivers side seatbelt extender doesnt work at all - appears to be no noise from it. I have also noticed that sometimes the passenger one operates when getting in the car - although only the drivers door has been opened and closed. Are they designed to only work on the side where a door has been used? If so would this point to a faulty relay (i.e. why does passenger work when not needed and drivers doesnt at all)? I have looked at wiring diagram and note that a lot seems to be operated by the "convenience module" - as everything else seems to work OK am I barking up the wrong tree? . Where do I look for relays etc for the extenders?

Sorry for such a long first post! Any help greatly appreciated!

Cheers
Adam

 

[Ian B Walker]

Adam, the first thing I would check is to see if you have any chafing of the wires as they go though the "A" pillar. It happens quite a bit on 124's. Silly question I know but have you checked fuses?. The multi function relay (the big long one in the back of the fuse box) give it a tap with something solid whilst a helper operates the various components.

 

[Howard]

Hi there,

Both seatbelt extenders come out when the drivers door is opened ...

 

[grenachenoir]

Ian - thanks for the ideas. Yes I did check the fuses - all seemed OK. Chafing wires sounds like a good one - do they go through the concertina plastic bit in the door shut? Presumably I just fully open door and pull that apart to check?

The big relay behind the fusebox, is that the "convenience" one? I'll give ita try anyway - thanks again for help.

Howard - brilliant - thanks for letting me know, it clears up one possible problem anyway!

Adam

 

[Sp!ke]

Hi there,

Both seatbelt extenders come out when the drivers door is opened ...

Not true Howard, mine only operate after its own door is opened. (Which is logical)

 

[Howard]

Hmmmm ..

When i get in the drivers side and sit down , both seatbelt extenders come out ....

When i clip mine in , both go away ....

Strange

 

[grenachenoir]

Well all, another little problem reared it's head today - not sure if it's connected! The boot lock failed to unlock with the doors. I locked and unlocked the boot a couple of times and then it was fine...until I opened the boot and the alarm went off very loudly ..didn't even know it had an alarm...I do now!

Anyway, locked and unlocked the front door and off went the alarm. Any chance all of these things are connected? Could it be one relay or ECU that is at fault? Would this be good or bad in terms of cost??

Havent had a chance to check for chafing wires yet.....

 

[Subyland]

In line with what Ian said, see if things work with the door opened. If yes=>chafing

 

[c955]

Not true Howard, mine only operate after its own door is opened. (Which is logical)

Ditto here.

 

[Howard]

Hmmm ...

Perhaps i need to have a look at this .....

 

[Ian B Walker]

Not true Howard, mine only operate after its own door is opened. (Which is logical)

Mine too, I even went out in the rain to check