W124 electric mirrors not working

[Dickie14]

Hi guys

I've just acquired a lovely 1996 W124 E220 coupe, and everything electrical works bar the wing mirrors. I suspected a fuse but according to the manual they use the same fuse (fuse 'B') as the seatbelt butlers and they both work... Checking out the fuse box anyway I couldn't find any that had blown.

Any ideas? Where should I look next? Would the switch itself be the next logical step, seeing as neither mirror works?

Thanks in advance for any pointers!

Cheers,
Dickie

 

[kingdave]

Hi Dickie,
I had my 124 in a garage for some work on the SRS -airbag system once, I'd discovered someone had removed the warning bulb in the instrument cluster from that some time in the past because it was showing a fault and I wanted to get it going again for safety, MOT and resale's sake. They fixed it, telling me they just had to reconnect a connector under the radio which is where the airbag ECU lives.
(sorry for the digression - I'll get to the point)...
When I got the car back, neither of the electric mirrors worked and I spent ages fiddling about with fuses because I couldn't understand it.

Eventually I went to have a look a the switch in the centre-console and on lifting the wooden panel I found the wiring had come unplugged from the switch. Ironic since it must have been disturbed when the airbag one was fixed.

It's easy to get at the switch, in-case you don't know:-
- remove 2 screws from the front edge of the inside of the centre storage box (if fitted).
- remove centre storage box
- remove single screw retaining the bracket which holds the wooden panel for the electric window, mirrors and gear lever.
- carefully lift the wooden panel from the rear electric windows end and take a look behind the mirrors joystick type switch.

Cheers and good luck,
Dave

 

[llewe]

My money would be on the switch, either the connection or the switch itself. Check for power at the switch plug in bit with a multimeter to be sure.
My switch was duff when i bought my car-someone had spilt sticky drink at sometime in the cars past which took it out along with two of the window switches.

 

[Dickie14]

Brilliant, thanks for the advice - I'll have a look under the console tomorrow. I'll let you know what I find...

 

[Dickie14]

Got the console up and everything was connected as it should be. Pulled the connector off the back of the switch and found there's no power getting to the connector... Time for another look at the fuse box I guess?

 

[coupe deville]

Both mirrors ooo and no power at the switch, my money is on the fuse, might not be blown, just grotty

 

[Dickie14]

I triple-checked the fuses then cleaned them and checked again for luck. Still no power at the switch. Is there another connector in-line somewhere in the wiring loom for the mirrors? Not sure what else to try now...

 

[kth286]

I triple-checked the fuses then cleaned them and checked again for luck. Still no power at the switch. Is there another connector in-line somewhere in the wiring loom for the mirrors? Not sure what else to try now...

The feed to mirror comes from the Special Equipment connector block.

You will likely find it in footwell behind side panel - driver side I believe.

 

[coupe deville]

voltage chase is
Battery, ignition switch, fuse box, special equipment connector block, mirror control switch, mirror motors.
You say no power at mirror control switch, so we're looking upstream of that. Check if any voltage on fuse,
yes, look at special connector block
no, look at ignition switch
and associated wiring for damage.
You'll need a meter and a flask of coffee

 

[Dickie14]

That wiring diagram's great, thanks Dave. With the ignition on there's power at the fuse, so carpets up over easter...

Is the Special equipment connector on the driver's side on RHD cars? I can only seem to find info/pictures about it on LHD cars, and I know Mercedes didn't bother to swap everything over.

 

[coupe deville]

Under the pedals


http://www.w124performance.com/service/w124CD2/Program/Chassis/54-5125.pdf

 

[Dickie14]

FIXED!

Turns out I was being a bit of a numpty - when I first checked the connector on the back of the switch for power, the ignition wasn't on! I'd assumed that as the windows had power surely the mirrors would too...

So the switch was at fault all along. I found this thread on this forum:

http://www.mbclub.co.uk/forums/electronics/4640-howto-blown-bulb-4-mirror-switch.html

...which gave me the confidence to pull mine apart rather than throwing £30 at eBay. Not entirely sure what was wrong with the switch as the microscopic components flew all over the place when I opened it, but after making sure my cat didn't inhale any of them and using my entire repertoire of swear words I had the b*stard back together, and now both mirrors work! Huzzah!

Thanks very much for the help guys, very much appreciated!

Cheers,
Dickie