Rear Window Defogger Problems

[XCHauler]

My rear window defroster on my ’01 V70 XC has stopped working recently and I am having some problems trying to find out what the problem is. The light on the dash is illuminated but the defroster is not energized in order to clear the ice and frost. I have replaced the 5 amp fuse in the rear fuse panel with a new one, although the exiting fuse seems fine. I was going to check the relay in the rear fuse panel and according to an image that I printed from AllData DIY the fuse should be in position #3. When I removed the rear trim panel I noticed that there was not a relay in position M13 in the fuse as the diagram indicates. There are relays in positions 1,2 and 4 but not in position #3 in which AllData indicates. Can anyone tell me which of these relays is used for the rear window defroster?

I have attached some images of my rear fuse panel.


I repaired a number of damaged wires that were bundled in a cover by the rear hatch hinged last summer that fixed some brake light and defroster issues and I made sure that they would stay together by soldering all of the connections and wrapping them with electrical tape. So I think that would not be the problem.
I pulled the battery and checked the 40amp fuses in the panel that are located adjacent to the battery and they appeared OK, but I’m not sure what a defective 40 amp fuse would look like?

Any help would be appreciated!

Thanks,
XCHauler

[hoonk]

Heres a couple of diagrams that might help. With the defroster on do you have 12V between terminal 1 and 14 on connector 54/50? (the red and the black wire) If yes test for power and ground at the glass itself to check for a break in the wiring that flexes when you open the cargo door. You could bypass the relay (terminals 1 and 3) with a jumper wire as a test also.


From your post "I repaired a number of damaged wires that were bundled in a cover by the rear hatch hinged last summer that fixed some brake light and defroster issues and I made sure that they would stay together by soldering all of the connections and wrapping them with electrical tape."

That might be the first place I would look (where it was fixed before) [happy]

56795680

[XCHauler]

I checked for 12V at connector 54/50 and there was no power at these pins. I also checked for any voltage at the 5amp fuse and it was dead. I'm thinking that the relay might be bad, but I am not sure which relay it might be (RMA1, RMA2 or RMA4) there is no relay in the RMA3 position which is designated for the rear window defroster. Any thoughts on which relay it might be would be helpful.

XCHauler

[hoonk]

No 12v at 5A fuse d5? From the diagram fuses d3,4,5 have a common power source, if the brake and reverse lights work (fuses d3-4) you should have power at least on one side of fuse d5.