most of the time on Mercedes the Windows stop working due to spilling your drinks and food on the switches, you may have to remove the switches take them apart carefully and clean all the debris out of them. I am giving you a component location to the window relay make sure it is working let me know what you find.

COMPONENT LOCATIONS

Component
Location
Convenience Control Module (1)
Location
Under left side Of Rear Seat

Convenience Control Relay (K24)
Location
Rear, Left Side Of Engine Compartment In Fuse Box

Front Door Pin Switch
Location
Appropriate Door Jamb

Fuse Block
Location
In Engine Compartment

Power Window Switches
Center Console & Appropriate Rear Door

Rear Window Safety Switch
Center Console (1)1990-95 vehicles are equipped with a 4-power window system.

Answered by Dr Loot (expert)
2,178 answers provided

I have checked the switches. I have ground going through the switch when it is pressed. I also jumped ground to the wires going from the switch to the convienence module under the rear seat and I cant make the windows move. When the switch is pushed and sends ground to the module there is no power and ground coming out to the window motor.

Response from chrisw3
1 question asked

So the next step is to find out why there is no power, check the K24 relay under the hood make sure it is getting power.

Convenience Control Relay (K24)
Location
Rear, Left Side Of Engine Compartment In Fuse Box

Answered by Dr Loot (expert)
2,178 answers provided

I do have power at the convienience module frome the k24 relay. so does that mean I have a bad module?

Response from chrisw3
1 question asked