Where exactly is the "Window Defogger Module - Rear"?

usa1169

New member
Putting a new stereo in my 2005 118wb Passenger I removed all the headliner and while it is open I would like to fix the rear window defogger that has never worked since the van was new. I have the manual and the wiring diagram. The 30 amp fuse is good, both relays under the driver's seat are good, the switch on the dash is functioning. All that is left is the mystery "Window Defogger Module - Rear" that page 8W-91 of the manual says is located "rear of vehicle". But I can't find the damn thing.

Anyone happen to know where in the rear of the vehicle they hid it??

Thanks!
 

autostaretx

Erratic Member
Good grief... the service manual's description is insane ...
as you wrote, they claim it's in the rear of the vehicle. (perhaps to sense the local temperature?)

But it's triggering the two relays located under the driver's seat ... the module's job is apparently to *limit* heating to 5 minutes or less.

This can be (painfully) gleaned from the "description chapter" starting at 8G-1

But they never show it, nor speak of repairing/replacing it ... not even in the "modules" section (8E-1).

The module makes use of C200 (under the instrument panel) and G202 (under the driver's seat).
It's hard to believe it's at the rear of the Sprinter.

I'd try back-tracking from the two relays' coil wires (which are under the driver's seat, and the dedicated fuse should make them easy to find)

Searching the parts catalog for "heated", "module", "rear window", "heated rear" ... does not show it.
Searching the Chrysler-to-MB part number cross reference file doesn't find anything obvious (there are 3 "Module"s with no defining 2nd word (unlike things like: "Module powertrain")

--dick
 
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usa1169

New member
Yup... you came to the same conclusion I did.

Another point to note is that there is only one relay labeled Rear Window Defogger under the driver's seat. My assumption is that the one labeled Optional Equipment is in fact the other window defogger relay, but I will trace from the nearby 30 AMP fuse they share and confirm that (thanks for the suggestion).

It may be time for me to break out the telephone line "toner" and do some inductive tracking of the wires to try and find the elusive Window Defogger Module - rear.
 
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