Rear Defroster

**makthenif** · 07-26-2007, 05:04 PM

The rear door defroster grids are not working on my '96 Sub 5.7. What should I be looking for to troubleshoot this problem?

**84fiero123** · 07-26-2007, 05:53 PM

You said door so I am guessing it has barn doors?

If so when you open them you will see a row of pins that look like copper. They corrode so they may look green in color. That is what sends the power to the door itself. When the door closes they come in contact with the door part of connection to the grid.

They get green and dirty, they don’t send power to the window grid. If they are dirty or green I have used fine emery paper to clean them.

But you also need to look at the grid on the windows themselves for any damage to the grid on the window. Over the years the windows get washed many times and if you are not careful you can damage that grid causing some of the grid lines not to work. They heat up and actually do the defrosting.

If the grids are not working in just a few places look for brakes. You can get a repair kit, basically a eclectically conductive paint. Use tape to make a nice clean line, brush on the paint in the places that the lines are broken. Let dry and recheck to see if they work again.

**84fiero123** · 07-26-2007, 05:57 PM

PS

I have to do the line fix on several of the lines in both my door grids this summer. You have to do the line repair in like 70 F or more. So this is not a winter repair, unless you have a heated garage.

If I remember I will do a photo write up with pictures on how to do it, STML, no guaranties on if I will remember.

**Cableguy** · 07-26-2007, 08:15 PM

Originally Posted by 84fiero123

They get green and dirty, they don’t send power to the window grid. If they are dirty or green I have used fine emery paper to clean them.

Emery cloth and then spray on some contact clean. I use it for trailer plug connector to keep it clean too.

**84fiero123** · 07-26-2007, 09:09 PM

Hey Jamie, seeing you are the electrical guy, somewhat anyway. Cable
What is a good spray to keep electrical connections from turning green, getting fouled.

**Cableguy** · 07-26-2007, 11:23 PM

I was an Electrician for a year before I started Cable, but the answer to your question is tough cuz one thing I have learned with cable is you can't stop water...All our repairs are water related in some way. So you can hold it back or minimize the damage it is going to do. I use silicone grease and contact cleaner(There is several different brands) in exterior connections. Huge fan of doing splices on cars/trucks with solder and heat shrink tubes. If I were to ask everybody to take a picture of there rear trailer plug I bet we'd be surprised (Unless its brand new)