Defogger not working: 1980 Honda Accord

[Klavier]

I have another annoying electrical gremlin to deal with in the car, it seems. My girl went to use the defogger, and nothing happened. The fuse is good, the button lights up when she pushes it in, but it doesn't work at all. I tried to test for voltage and resistance across a few different points, I could only get sporadic, inconsistent, weak voltage very close to the tabs that connect to the glass. Not sure if the multimeter I used also sucks, but that's possible. Any ideas? She's sad that it isn't working.

[Dr_Snooz]

The first thing to do is look over the back window for any sections where the defogger wires have been broken or scraped off. You can buy special paint to repaint any wires that have been damaged. From my experience, however, the defogger wires themselves develop too much resistance over time. That's why you're not seeing any current on your voltmeter. The only real solution is to replace the window with a new one.

FWIW, if you set the front defroster on high, it will eventually blow across the top of the cabin and clear the rear window. That's how I cleared the window on my '76 after the defroster pooped out.

[SjNoob]

Break in the wire and earthing somewhere?

[Klavier]

SjNoob: Earthing = grounding, yes?

Dr_Snooz: Interesting theory, you think that those wires painted on the glass have corroded? That's obnoxious. I'm going to hit the whole window with some contact cleaner, as I have no idea where I would find a new rear glass assembly.

[SjNoob]

I actually have the same problem. When you press the switch it lights up. But I see no difference in the rear window.
Only thing I can think of is chasing the wire back to the front of the car.

[Klavier]

Can't be a fuse either, because that fuse controls the radio as well, and the radio is fine. Meh.

[SjNoob]

hahaha strange...

[Klavier]

I tried following the wire in a junked '81 Accord sedan I was salvaging a window regulator out of, it was a total pain in the ass and I gave up. I think that part of the car is going unrestored.

[2ndGenGuy]

Yeah, mine works in my car, but it's pretty weak. It's one of those things I've never really been sure about how to fix...