Couple of minpr CL500 electrical problems

[Will Barber]

As some of you know I've just picked up my 2005 CL500. What a car... so happy everyone said go for it!

I have two small electrically related problems with it... the first one is a bit confusing.
1. The rear electric window switches (in the rear cabin) do not light up or work the rear windows. The rear windows can be controlled with the drivers switches and I've tried sliding the isolation switch in both directions but to no avail. Fuses check out okay.
2. Both the driver and passenger seat lumbar supports are non operational. These are heated/cooling seats without massage function. Again ALL fuses check out okay. I've taken out both lumbar control switches to check and they're okay. I wouldn't have thought that the vacuum hoses on BOTH seats have failed, besides they look very pliable and intact. Obviously they are 100% pneumatic as there are no wires going to the switch, the 'thumbwheel' switches are simply valves.

Thank you for your time, very appreciated and I appreciate any help as always.

Kind regards, Will

 

[television]

I will take a look to see what is common for your faults Will later in the day.

 

[television]

Having had a good look around it could be broken wires in the drivers door, but the same on both side cancels this out in many ways.

Have you checked F72, F74

 

[brandwooddixon]

It could be that the wiring for the rear window isolation switch has broken in the door hinge area.

As you have already noticed that lumbar support is pneumatic. It may be that there is a leak and the pump has isolated the feed to the seats. Try removing and reinserting the large 20Amp fuse (yellow I think) in the fuse box at the base of the rear seat to reset the pump and then try.

 

[Will Barber]

TV - ALL fuses check out okay. Thanks.

BWD - I will check the hinge wiring as recommended thanks.

Will also try the fuse R&F to see if this pulls the pumps in. I take it that there is only one fused circuit then for both driver and passenger seats then.?

One more question.... If I disconnect the battery neg terminal, will this empty the vehicles ECU's of any fault codes (like it does on VAG vehicles) and will I need any codes for the COMAND system.

If everything checks out akay with the above, then obviously the next step is to visit a MB dealer to hook up to STAR to see what's going on (unless anyones knows of a STAR equipped non franchise dealer in my area of South Cheshire)

Many thanks as always, Will.

 

[television]

Indeed disconnecting might fix it all if all locked up..

The only thing to do when reconnected is to re set the windows and the ESP lamp will go out as you drive