Hey all... I've got a pretty bad problem here (atleast in my opinion, here in Canada..).. When I turn on my rear defrost, it pops the 30A breaker in the drivers side fuse block... and I need the rear defrost to work, since its cold out, and if I don't let the car run for 5-10 mins before I go out, my windows will fog up... Any ideas where the short might be? The breaker gets really hot when it trips..... so I know its a power grounding out.. but where..

And one more thing... the engine in this car didn't have any coolant in it when I got it, and yes, she was overheated enough to turn the metal on the spark plugs blue, which have been replaced, but now, I get a low coolant light come on all the time... I'm assuming that there is an air bubble in the system somewhere, but how do I get it out, or is it the coolant level sensor that is flakey?

On your rear defrost:

You have a short to ground or a weak breaker. Are you running metallized tint on the rear window that could be shorting the grid? Anything on the rear deck that'* touching two lines? Any damage to the wiring harness?

On the low coolant light, check your radiator level. That'* all that matters. The sensor is on the back side of the radiator near the top. If the radiator is full, remove the sensor and clean the face of the sensor if it'* gunked up. If not, either replace the sensor or simply unplug it.


I'll move your topic to Electrical. Both problems seem to be going in that direction.

As far as I know, the wiring is intact for the rear defrost, and no, there is no tint in the car yet, that is something I'm looking at doing next year.. I'm thinking that there is a bad ground somewhere or something.. I just don't know where the wiring runs for the defrost... is there any common problem areas that corrode that I can maybe clean up/repair?

I didn't know where the low coolant sensor is located on these cars, since I didn't have this problem on my 90, but good to know that it is on the rad.. I'll see if I can take a look at that today or tommorow...

It cannot be a 'bad' ground. If it were, no current would flow in the circuit, and no fuse or breaker would pop.

It has to be a bad POWER wire, shorted to ground where it shouldn't. Power short to ground, that'* what you're looking for. Forget the ground side of the circuit entirely. OR a weak breaker. Don't rule that out.

Look at your radiator. On the back side of it near the top, you'll see the sensor. They're the only two wires actually going TO the radiator.

Interesting - I too, am having issues with the Rear Window Defroster/Power Lock circuit now that winter is upon us... :(
When I turn on the Defroster, after a couple minutes it shuts off [way before it used to, & way before the window is clear] and then won't allow me to turn it back on. After this happens, the Power Locks don't work.
If I wait a while, the Power Locks work again. :?

In your case it may be the ground buss by the front pillar under the door trim. I had a 93 where the door locks and the AC control would both quit for a period of minutes or until the next restart. I had decided it was the ground. Never took it out; my wife traded it for her new shiny one first. I never checked the rear defogger to see if it quit working at the time.