surferfrank

I have a 1990 4 Runner with a heated rear window defrost problem.
It seems a portion of the metallic strip near the bottom has been worn out and the window defrost doesn't work. Is there a way to make the electrical connection again? (cheaply, of course).

There is a another window defrost on the side glass which also doesn't work.

I couldn't find any threads on this issue, so any help would be appreciated.

Thanks

TechWrench

There is a repair fluid in a bottle that is used to repair small cuts in the grid. You should be able to find it at most auto parts stores. If you know where the cut is, you just paint over the cut to restore continuity and it should work. If you have a large part of the grid missing, this stuff won't work well.

If you don't know exactly where in a particular grid the break is, you will have to use a meter to locate it.

Gangus2006

RadioShack has the electrical conductive paint in a pen...

leebee

i have a similar problem with mine, the right side has two tabs with little connectors to power the grid. the outboard tab on the right side has broken off, im going to scrape away some of the coating on the parts and solder them together. it would be a good idea to use a hair dryer on high setting to warm up the glass first, you dont want to apply the solder and have the heat shatter the rear window because its cold.

lee

surferfrank

Excellent! I may have to take the window out if the break is under the panel. This is great news, especially since the winter is coming.

thanks for the information.

TechWrench

Considering you last post, maybe I should clarify a couple of points.

There should not be any grid lines under any panels, the material used to make the grids can be easily damaged, and the manufacturer wouldn't install it so that contact with other parts could damage it. Only the visible grid on the glass is supposed to heat up. As with any electrical circuit, there should be two terminals connected to the grid, a positive (+) and negative (-). If none of the grid lines are working, you most likely have a problem with the source power supply to the grid, or the associated wiring. If only a few of the grid lines are not working, then it is a problem with a break in those lines.

surferfrank

If the connectors are ok. Can I "paint" on the conductive film to fix the problem? It seems the window scratched off about one inch of film. Thanks for the updated info.

fh

TechWrench

As long as the power connectors are intact and working you should be able to repair the damaged grid/grids with the conductive paint. But, if what ever damaged the grid in the first place is still hitting the window, then the problem will return.