Rear defogger not working

[Cameron]

I have a 96 yukon 4x4 4dr with barn doors. When I bought it I had to replace the a/c control panel my rear window defogger does not work. The button lights up but the only clicking I hear is the switch itself is there a relay somewhere maybe? I have tested the plugs at the rear windows and recieve no voltage.

 

[Cameron]

No clue?

 

[trevcda]

Have you checked to contacts between the body and the doors?

 

[Cameron]

After reading your reply and going back and looking at the wiring I was an idiot and tried to read the wires connectors inside the doors with the door open. I completely overlooked the contact points on the body of the truck I will be going back in about an hour to check at this point. Stupid mistake lol

 

[trevcda]

I didn't want to say it so obviously, especially if you already knew it, but that's where I was trying to lead you!

Anyway, sometimes those contact points get dirty and don't make good contact and won't allow the circuit to complete. Usually gently wiping them will allow them to function correctly. I don't know, but a I presume there is some sort of coating to prevent corrosion, so I would steer away from harsh chemicals that might eat away at any protection that's there.

 

[Cameron]

Well I just checked the contacts on the body and got 11.7 Volts on both sides of the truck. So it should be working I'm going to clean the contacts and try it in the morning and see if that's what's wrong.

 

[Cameron]

Well this morning it did not work after cleaning the contacts. I'm going to test the resistance on the wires in the doors and test the voltage at each connector in the door with it shut. It should be somewhere in there because one glass is less than 8 months old bought new not used.

 

[bowtiefreak]

Clean both contacts really well and get some electrical grease and put that on there. Just did it to mine and it is working again. I used a scotch bright pads and polished them up really well

 

[Cameron]

I will be sure to do that as soon as I get off work. They seem to look clean on the body side but I'm going to make sure and add so di-electric grease to prevent corrosion like you said maybe that will solve it. I hope so.

 

[SunlitComet]

better to clean or replace then trying grease in the long run for protection on those parts.