02 Impala rear defogger no work...maybe the "breaker"

[GJD5]

I've been trying to figure out what's wrong with my dad's 02 impala rear defogger. There is a fuse block on the passenger side (near the door jam) and the label shows there is a 30 amp defogger breaker there. I don't see it...maybe it's behind the fuse block? How the heck do I get to it and check it? I've never seen a breaker before in a car. I did check the relay in there and the relay itself is good. Any ideas? The light on the dash does light up when you press the button.

[rockfangd]

sounds like a problem with the grid. Start with checking the solder joints on the left and right of the rear window for broken connectors and then check the rear grid for a damaged section.

[GJD5]

There is a continuous circuit from each connector, so the grid is good. I read somewhere about a antenna module or something on the C-pillar that can cause a loss of power to the defogger...anyone know more about this or where exactly it is?

[rockfangd]

that one i do not know. Did you test the connectors at the rear window to be sure it is getting ground and power. SO basically when it is on there is no power at one of the connectors on the rear window

[GJD5]

So, we have narrowed the problem down a bit more. The problem is that when you push the rear defogger button on the dash it is not engaging the relay. Relay itself is good. The main power source to the grid is good, ground for grid is good. It's just that the the control unit is not sending voltage to the relay and so it's not closing the switch to apply power to the grid. Anyone have a wiring diagram for a 02 impala defogger? Probably the control unit at this point but I'd like to see if there is anything else I missed.