Rear defrost isn't working and the light is always on. It will not turn off. Fuses appear okay and interior dome, rear wiper and window work fine. Any ideas? I wasn't able to find anything thus far.

 

A quick and easy check: The wiring under the rubber boot between the hatch and the body. One or more of those wires are often broken, there could be a little electrical shenanigans going on there. It'd be cool if it were something that simple.

 

Sounds to me like the switch is Fubar allowing the light to be on but no voltage to the defrost grid.

 

Checked the wires. They seem okay. One had a crack but was still intact. I'll work on the switch tomorrow. I have an extra dash setup and will swap it out to see if that is the culprit. Thanks!

 

Okay so I put another switch in, no luck the light still lights up. To recap, The connections on the rear window seem to be okay, the wires seem to be okay. Relay is in place and I tried another switch. Any ideas?

Thanks!

 

You did test both switches with your meter to make sure they were good or bad??

Could be both switches have failed in the same manor.

You mean the light is on all the time??

once the ignition is turned one.

it means for some reason the part of the switch that has the light is able to complete the circuit to ground .

Which allows the light to be on.

 

what year 4runner?
If up to 98, then most likely the relay is back feeding the switch as its shorted out. If 99 or newer, it has a body ecu that controls the rear defrost and side mirror defrost. The "body ecu" is built into the fuse block thats in the driver knee area.