Rear defrost not working

[hearno]

I'll start by saying I'm familiar with the rear window lock out feature for the wiper and defrost if it's not rolled up completely. My rear wiper works and the rear window works as it should. All of the searching I've done has brought up threads on that issue. I have eliminated that as the cause of my issue. I hit the dash button and the orange light turns on indicating the defrost is on. My issue is that it barely works. The window only clears maybe .5mm on top and bottom of each of the defrost lines in the rear window. I would think it's an all or nothing feature, it either works or it doesn't. Is possible there's a ground or short that could cause it to not work at 100%?

 

[4x4mike]

Check to see if there are any cuts in the metal striping on the glass. You can also check the continuity with a multi meter to see if the circuit is not complete. If it's broken you can get less than full power or uneven defrosting.

I've got a 3rd gen and when the defrost button is pushed the side mirror heat is activated at the same time. Is this the same on your 4th gen? Do the mirrors get warm when the button is pushed?

I had warm mirrors but no window defrost and found that one of the power wires to the rear window had broken off the window. As the window goes up and down I think the wires just hang. One of mine decided to come unglued/attached.

It required taking the hatch plastic off and working overhead but it's worthwhile to check out.

 

[hearno]

Hmm, I have no idea how to use a multimeter. Hopefully, a local auto parts store will have one to loan and an idea of where to test and which setting etc. I will check to see if any of the strips are broken, didn't realize it wouldn't work if there was a disruption. I did find repair kits via google and it looks like a simple process to fix the lines. Unfortunately I don't have heated mirrors, I wish I did tho. Thanks for the reply.

 

[Bob J]

Hmm, I have no idea how to use a multimeter. Hopefully, a local auto parts store will have one to loan and an idea of where to test and which setting etc. I will check to see if any of the strips are broken, didn't realize it wouldn't work if there was a disruption. I did find repair kits via google and it looks like a simple process to fix the lines. Unfortunately I don't have heated mirrors, I wish I did tho. Thanks for the reply.

Here's a link showing how to find the breaks and do the repair:

How to Repair Your Defroster Grids

https://www.youtube.com/watch?v=FSPdfjCbHX8

 

[nevada]

I'll start by saying I'm familiar with the rear window lock out feature for the wiper and defrost if it's not rolled up completely. My rear wiper works and the rear window works as it should. All of the searching I've done has brought up threads on that issue. I have eliminated that as the cause of my issue. I hit the dash button and the orange light turns on indicating the defrost is on. My issue is that it barely works. The window only clears maybe .5mm on top and bottom of each of the defrost lines in the rear window. I would think it's an all or nothing feature, it either works or it doesn't. Is possible there's a ground or short that could cause it to not work at 100%?

that indicates there are no breaks in the lines.

it sound like a bad connection somewhere. its not getting the full voltage it needs.

 

[hearno]

that indicates there are no breaks in the lines.

it sound like a bad connection somewhere. its not getting the full voltage it needs.

Does that mean get the multimeter or some other avenue?

 

[nevada]

Does that mean get the multimeter or some other avenue?

yes, you would still need to meter it out to see what you're getting at the lines.