How To Repair a Rear Window Defrost Grid Panel

How To Repair a Rear Window Defrost Grid Panel

Brought to you by Your source
for quality replacement parts and the best service on the internet. 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.

About the Author: Michael Flood


  1. Great video. Do you happen to have a repair kit for when the metal tab and wire break off a hatch back glass such as an S10 Blazer?

  2. I agree with everyone else, good video and easy to follow. One question I've got though is, do you know where someone may find this compound to use? I've searched several places and haven't had any luck finding the compound myself.

  3. I bought a test light that didn't show any current flowing through the defogger grid–even the lines that I KNOW are working. Is there a specific kind of light I'm supposed to use?

  4. What about if you have tinted windows?
    By the way i have this problem with like 3 lines cause its previous owner took her stickers off the window damaging the defrost and the tint .-.

  5. As a mechanic, I've enjoyed many of your videos. This is one of the most informative and easy repairs to follow. Such a wealth of knowledge in a short video.

  6. Hi! I came across your great videos today while searching for the answer to how to fix my rear window defroster. It's not a problem with any line on the grid… the whole grid isn't working. The little light on the dash comes on when I push the button, but it does not defrost the window. I tried unplugging the plugs on the back window and then plugging them back in. That didn't work. I tried unplugging the fuse and then plugging it back in. That didn't work. Can you make a video on how to diagnose why the whole thing isn't working? That'd be SO helpful. (My car is an older chevy cavalier if that helps.)

  7. You're the only video I found after watching a handful of others that addressed the issue I am having with the wires being broken. I can visibly see the breaks, and will be trying to get this repairs on my own. Thanks for saving me a $90 diagnostic fee at the dealership mechanic.

  8. Do you have advice for installing a complete new defroster grid panel on the windshield? I have an old volkswagen with no heat or fan and this would be a perfect fix.

  9. The panel that heats up the grid has detached from my truck… It is dangling.. Is there a video how to repair that?

  10. Ten likes by me! Nice tutorial never knew there is repair paste like this, so no more excuses by myself it's time to repair my broken def. grid.

  11. how much is this repair compound ? ? and how many inches of repair will 1 bottle do ? bought a car that is missing about 1 foot square from the middle 4 rows from a window sticker some one put in the middle.

  12. Great video but I would've liked to see the retest. Also, can this type of repair work if you have your window tinted??? Thanks for you help!

  13. Thank you so much for this video…I didnt know what was wrong or if there was anything I could do myself to fix it. Excellent video. Thanks again.

  14. So I just tested my defroster lines like you did, there are no visible breaks but the testing light gets dimmer as moved from driver's side to passenger. About 2/3rds of the window(starting from driver's side) you can visibly see it light up, the last 3rd(passenger side) does not light up….I checked the passenger side connection site and looked fine. Does this mean there's a dissipation in voltage across my lines? Also I checked all my fuses and relays that had to do with "Defog" and everything seemed alright there. I have a 2008 Mazda 6S. Let me know if you have any solutions or suggestion!

  15. Is there some kind of resistor between the battery and the power bus?…how does it not melt the copper being hooked up to 12vlt.

  16. The muzak contributes nothing here. It's actually very distracting. Why do so many people persist in accompanying their videos with inane noise?

  17. You asked to let you know what we think… overall I love your channel. This video was helpful… I would suggest editing out some of the down time like when he turns the keys and I would also suggest running the test light after the repair to make sure you got it (looks like the top line has multiple breaks or a long break).

  18. hi sir
    I want to ask if it's possible to use electronic voltage pen to test the defroster grid or I have to use the same tester you are using

  19. Do you know if the same type of repair kit can be used to repair the Radio antenna that's embedded in the rear windscreen of my E39 BMW 540? I had rear tint removed and my radio stopped getting reception, so I think that's the issue

  20. Is there any reason this technique will not fix the FM antenna grid that is built into some cars rear windshield above the defroster grid? I bought a kit that was sold for defroster repair and he is saying it will not work for the antenna, but the grid lines look exactly the same to me.

  21. What do you do if one one side of the wire grid works and the other side doesn't but it isn't the grid it's in the wiring?

  22. You know I saw in the dealership and they sale aside the mirror with heated, and it fit perfectly in my Honda CR-V LX, but I checked my car and it didn’t come with electrical wiring for that, do you know if it will be possible that I can do the electrical wiring and it’ll be work? (Mirror heated that I saw it’s for crv models superior that I got). Thanks

  23. my grids on a 2010 Explorer just started falling off. By the time I buy paint, I might be better off just buying a new window. but good video. you didn't talk too much and got to work

  24. Only one minor comment. If there's only one breakin a gridline, it won't matter, but using a test light and this method will take as many days to fix a broken grid line as there are breaks in that line. It is easier to assume multiple breaks and use a ohmmeter straddling one section small section of the line at a time. If you check a similar length piece of a good line, you'll have a reference.

  25. Does tinting the rear glass with grids affect the normal operation of the grid lines as it heats up? I want to tint mine but don't want to damage my rear glass defrost. Thank you.

  26. My windows are tinted but some of the lines on my rear defroster are going off can I apply this on the lines with my windows already tinted ?

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