I'm stumped on the rear wiper and washer motor. I now have 3 motors that I can jump off/hot wire and they run...but they won't run installed in the car.

1. I've removed and cleaned all the switches, tested, they work.

2. put in a different relay, the one in the wagon door, I can hear it click, it is getting juice at least...how would you test it?

3. Cleaned, relubed all the motors, all 3 run smooth and easy when hot wired

4. I can jump wire and squirt the rear washer pump..but again, not in the car

This is starting to sound like a relay....again.

Is there another relay somewhere else on the wagons? There are 2 up under the hood in the black plastic box...what do they do??

Anybody have the MB manual on testing the system?

Any ideas at all??

__________________
Mark
1983 300TD Wagon
Even a broken watch is right twice a day

Rear wiper wiring diagram.
http://mb.braingears.com/123_DISK2/program/Chassis/82-780.pdf

I'm pretty sure the two relays up front are for the A/C system. (A/C clutch and fan)

Thanks Forced! Too bad I read Chinese better than I read these diagrams.

Still, it LOOKS like I could jump/bypass the 5 pin wire off the interval relay and that would tell me if the switch worked and if the relay was bad...you think??

M8, M9...I check those grounds. Don't recall cleaning those on my inital sweep of the car.

__________________
Mark
1983 300TD Wagon
Even a broken watch is right twice a day

I think #2 and #3 are labeled backwards. You might also check the connector above the back door.

Good catch on 2&3 being miss labeled...even I should have seen that! Thanks.

__________________
Mark
1983 300TD Wagon
Even a broken watch is right twice a day

BUMP...where are you Wagonmasters? Or am I the only one in the world with a bad rear wiper? (Does that make me special??)

Jimmy? Bio300td??

__________________
Mark
1983 300TD Wagon
Even a broken watch is right twice a day