2002 Monte SS.
I am at a loss for what to check next.

Rear defroster is not operable.
Power light comes on when pressed on the HVAC control panel.
All tabs connected to rear winshield.
Pulled the passenger side fuse box.
30 amp. Breaker is good. EXCHANGED , tried both breakers in the power seat slot.
Exchanged both twice , power seat worked with both breakers.
No wires or the actual fuse box is showing any signs of an overheated connection.
Removed the gray cover. No charing is evident.

I have seen the threads about this problem. The last thing to check is the elusive
" antenna " box connection . Radio works fine , both AM /FM.

Where is that " box " ?

Thanks Guys !!!

 

Don't bank on that breaker being good because it worked with the power seat. Circuit breakers wear down (even ones in your home, especially the more they are tripped). The seat may not draw enough juice to cause the breaker to activate.
Such as on my Monte, I could do a continuity test on the original breaker and it worked. In theory, that should not be my problem. But, because it was less then $10, I bought a new one from the parts store and put it in. And now my rear defroster seems to work great (granted I only use it early spring and fall as my Monte is parked for the winter).

I would advise full out replacing the breaker, even though it appears good.

From what I understand, when the antenna/defroster module fails, you typically have radio reception problems when the defroster is on. If you still wish to hunt it out, if I recall, it's behind the rear passenger side sail panel trim, new the rear speaker deck. It's also a dealer only part (last I heard $20-$30).

 

Thanks Maniac...

It is cheap enough...I will give it a try.

Was working last season. Just stumped !

 

Have you checked the relay?

 

I have two relays that I have tested in the same plug in position. Does orientation of the relay make a difference ?

I do hear " clicking " in the passenger side side fuse panel.

But , still not working on the rear windshield.

 

If I recall, with that relay, the orientation does not matter. If you here it clicking, odds are high, it's doing it's job.

 

So I used a multimeter meter to check the volts at the connecter to the winshield. 14 volts at the plug.

I did use the Permatex kit to reinstall the tab. Some time ago. To the letter on the directions. Tab is firm to the glass. Matter of fact I have pulled the plug connector on / off several times to check. No release.

When I put the spades from the multimeter to the tab , with the connector connected.
14 volts on the tab.

No breaks in the defroster grid. Worked last season. No kids or cargo in the back to scratch the grid. I notice that around the tab connection location some of the dark " clay " colored material is missing.

Wonder if the grid " paint" would close the connection. That could be my problem.

 

The dark clay that's missing....

Is probably solder... If that's missing... that's more than like you missing connection!

 

I have never had good luck with that kit. I went to a Safelite Autoglass near where I live and they used this Conductive Epoxy and my rear defrost worked fine after that. They also did it for free for me, but that might have been because I was there having a windshield replaced for a friends car like 2 weeks before. Call a Auto glass install place and see what they say.
Hope that helps