2000 Corolla Rear Window Defrogger/defroster

[Ponder85]

My 2000 Corolla's Rear Window Defogger is not working.

I have searched google and the forum and found no relevant info to my particular problem.

The light on the instrument panel comes on.

I removed the trim from the CPanel and checked for continuity from all the grid lines to the connector. They are fine.

I do not have power at the connector with the Defogger turned on.

From a wiring diagram that I found, but could barely understand, it looks like the relay sends power to both the defogger and the defogger light on the instrument panel. I could be dead wrong on this however; it is just my understanding of the diagram. Also, I assume this does not completely eliminate the relay, as the light could be receiving power, and the defogger not.

My questions are, where is the relay? And what else should I be looking for?

Thanks in advance!

[Buurin]

The relay is on the back of the instrument panel junction block.

This is how to get at it:


This is the junction block removed:

The left relay in this pic is the defroster relay.

I marked where connector IH goes and its pin 2 for the unused S-HTR circuit. The unmarked pin is pin 1 for defroster. Probe for continuity between the wire from this plug to the defogger. If you have a factory-grade diagram, that circuit goes through IG2.

If your defroster indicator light goes on as expected, that wire is just about the only suspect left.

[Ponder85]

Wow, extremely helpful. Thank you very much. Ill check ther to see if I have power there. Looks like I'll be running a new wire.