No Rear Defroster

[78mc-bbc]

So on my 04' Suburban my rear defroster has never worked since i've owned the truck. The fuse is fine, the rear wiper works fine, the rear wire connectors are still connected to the glass, the mirrors still defrost when i hit the button.

Is there something else i can check?

 

[dropmech]

Check the individual lines themselves that go across the window. You may have some that are damaged. If they are, the autoparts store sells a repair kit for it.

 

[78mc-bbc]

none of the lines in the window seem to defrost,

 

[78mc-bbc]

Is there a relay for the rear defroster that can be bad? if so where is it located so i can check it out?

 

[dropmech]

There's a relay box under the hood on the driver side front. Not sure if there's one there for the defroster but there's a diagram under the cover.

 

[alacran]

i cant figure it out either.

 

[Zigger21]

So on my 04' Suburban my rear defroster has never worked since i've owned the truck. The fuse is fine, the rear wiper works fine, the rear wire connectors are still connected to the glass, the mirrors still defrost when i hit the button.

Is there something else i can check?

If you have an ohm meter you can check each individual line for continuity. There may be a break at the beginning of the circuit then its an easy fix just use defroster repair kit which is $1.99 at Napa. I hope its something simple like that

 

[78mc-bbc]

There's a relay box under the hood on the driver side front. Not sure if there's one there for the defroster but there's a diagram under the cover.

The diagram under the fuse box does not show a relay for the rear defroster, only a fuse which is fine. But if i look up a rear defroster relay at napa or other parts stores it shows one, but no location for it?

 

[78mc-bbc]

ok i found the relay it is under the dash in a small box where the plug for the trailer brakes harness is located. i replaced the relay just have to check to see if it works now

 

[caminohill]

also check the ground!!!

 

[78mc-bbc]

so the rear defogger still doesnt work, where are the grounds?

 

[nicegy31]

ok first thing you do is turn on the defroster and take a digital meter set it for low voltage dc. I had an similar issue and it was the connectors. If you have 12 volts at the two wires going to the window everything is fine. Just check the tabs on the window mine had a little paint on it and I had to clean them off with a small screwdriver and after that I tightened up the contacts on the connectors themself. If you do not have voltage you can go to the wiring and relay for troubleshooting.