rear window defogger

[ZiggyPA]

When I turn on the rear window defogger, after a brief period, many electrical options stop working. Such as the power seats, rear view mirrors and central locking system. When I turn it off (or it deactivates by it self)
after a couple of minutes everything works again.
Is this some kind of overload protection or if not, how can I fix it?
It is extremely cold overhere so I use the rear defogger almost continously...

[HotZ28]

For a success story; Click Here
Also, check the ground bus for corroision that is located under carpet, drivers side.

[ZiggyPA]

Thanks Hotz, I started to clean out the terminals with a sandpaper nail file. I only drove a couple of miles, but everything kept working. Last time I drove a couple of miles this was not so.
Don't know if this is a coincedence and it is already fixed now, but I think you hit the nail on the head and will proceed to swap the contact breakers and so on if it doesn't work.

Could this also be the problem lots of people are having with the sunroof operating intermittently ?

[ZiggyPA]

Several hundreds of miles later everything still working fine :-)
It seems the terminals were indeed the culprit ! Thanks !

[ZiggyPA]

It worked perfectly for exactly a month, but the problem came back. I cleaned out the terminals again but to no avail.
I wanted to exchange contact breaker #3 and #4, but #4 was so hot I actually burned my finger. Is this normal it gets that hot? The defogger had been on for about 30 minutes, but it was barely working. #3 (power windows and roof) was also warm, even though I had not used those.

[HotZ28]

The defogger should stay on for 12-min & automatically cut off. Are you manually reseting it? If it does not shut off, you may have a control problem. If the circuit breaker is getting very hot, I would suspect a poor connection at one of the terminals. It may be time to remove the right rear pillar cover between the headliner & rear deck & check the defrost module & terminals. Corrosion, or damaged terminals can cause excessive amperage draw.

[ZiggyPA]

It does cut off after about 10 minutes, I am manually turning it on again.
Is this right rear pillar cover hard to remove?

[HotZ28]

No, the cover pops off fairly easy, but you should use a trim removal tool to wedge behind the plastic retainers for removal, otherwise you may break the retainers loose from the side cover.