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How To Repair a Rear Window Defrost Grid Panel

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  1. step : Testing the Grid Line (1:30)
    • Turn the defroster on
    • Ground the test light
    • Test each grid wire
    • Find the break by starting at the closest point to the edge of the window and testing the light
  2. step : Repairing the Grid Line (2:44)
    • Place the mask over the broken grid line
    • Apply the compound with a small brush
    • Wait 20 minutes before applying a second layer
    • Wait 20 minutes before applying a third repair
    • Let the compound dry overnight
    • Remove the mask
    • Ground the test light
    • Turn the defroster on
    • Test the grid light
    • Repeat the repair procedure in case of any more faults

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Hi, everyone. I'm Don from 1A Auto. In this series of videos, we're going to be focusing on vehicle diagnostics and maintenance tips. We hope that you find it helpful, and when you need parts for your car or truck, think of Thanks.

In this video, we're going to show you how to diagnose and repair your defrost grid on your car or truck. It's pretty much the same operation for any car or truck with the grid that's built into the glass. So what are some of the common problems that you're going to run across or reasons why the grid goes bad? Well, for instance here, you see that we've got a sticker on this one here. If somebody were to scrape it off with a razor blade and unknowingly, or not realize that they're taking the grid off, well, then you're going to have a problem and that grid line isn't going to work.

Basically, the operation here for the grid working is power coming in, and then a ground on the opposite side. The power goes through, heats up each one of these wires, and then melts the snow or defrosts it. But once there's a break in one of these wires, that whole grid line is going to stop working. So, what we're going to do is walk you through how to diagnose why or where for that matter, your grid is broken so you can use repair kit and fix it so you've got all your grids working. All we're going to need is a little test light, so let's go in and let's get started.

All right, so I'm going to go in, I'm going to put the key in position two and turn the defroster on. I've got my test light. I'm going to ground it off to a good ground. This is a door striker. Anything metal that's grounded to the body will work. I'm going to go up to the grid, and I'm going to start testing. Nothing here. It's good. Not good. Going all the way down. Okay, so we've got an issue with the first and the third grid wires.

Now, in order to find out where your break is, you're going to start from the closest point and work your way out, and once you've lost voltage, you realize that there's a break in between here and here. This looks like we're going to need to repair it. Now on this third one, we'll start in the same spot and we're good to work our way out. Still good. It appears there's an issue right here. We're going to go ahead and repair that.

All right, so here's our kit. It's comprised of the compound which is the quick repair grid compound, a little brush to apply it, and a mask so that you can keep in straight in the lines of the grid. With this particular one, we're going to remove this and we're going to place this over where we know our fault is. Just like this. All right, then depending on which compound you get or brand, read the instructions as to how to apply it, but with this one, just give it a good shake, insert your brush, then go ahead and paint it on.

So we've applied our first coat of the repair compound. What we're going to do is wait about 20 minutes, do it again, wait another 20 minutes and do it again. Then let it dry overnight. Remove the mask here, then we're going to, tomorrow, put our test light on a good ground, just like we did before. Turn the defroster on and work our way out again with the test light to check for any other faults. If that is the case, we'll go ahead and repeat the procedure there.

We hope this video helps you out. Brought to you by, your source for quality replacement parts and the best service on the Internet. Please feel free to call us toll-free, 888-844-3393. We're the company that's here for you on the Internet and in person.

Tools needed for replacement:

    Diagnostic Tools

  • Test Light

  • Materials, Fluids, and Supplies

  • Defrost Grid Repair Kit

Voltage Circuit Test Light

Test Light Performance Tool

This part replaces:

  • Performance Tool W2975C

Part Details

  • Lead Length: 42 in. Lead Wire
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