rear window defroster problems

[jagoulet]

hi!

I have a 95 Legacy Wagon. The fuse for the rear window defroster

blew not long ago. I tried another one. In the brief time it was on,

I picked up some static in the radio. Then the fuse blew again.

 

Anyone got the part of the wiring diagram that has to do with this?

 

Does the switch directly provide power to the rear or does it activate a relay? The circuit has a 20A fuse so some decent current flowing. The wires to the switch near the steering wheel don't look especially heavy, making me wonder if there is a relay somewhere.

 

Any help appreciated!

 

John

[jagoulet]

after some scouting around I came up with a wiring diagram and learned there is indeed a relay involved.

 

I need to locate it and perhaps bench test it.

 

Do these have any history of failing? The car has any number of relays. Mine is ancient - 260K miles - so I can't blame it if it did.

 

I can find replacements available which would seem to suggest Yes - - people do need them on occasion.

[johnegg]

check the wires where they jump from the chassis to the rear hatch.

it is a common failure point for rear wipers,

so why not rear defrosters.

 

i do not know about relays,

but i'm pretty sure the negative return wire is switched.

 

HTH.

[jagoulet]

I have gotten into the tailgate and familiarized myself with everything but found no bad harness or wires.

 

I also got a wiring diagram and found there is a "condensor" in the circuit which I suspect is what most of us call a capacitor. Looking at the circuit, if the condensor were to fail, it would result in a direct short.

 

This would be easy to check out with a multimeter . . . if I knew where it was.

 

Anyone have a sense of where to look? Near the fuse panel down by the driver's left leg? Somewhere else?

 

thanks for your time!

John