My windows are not defrosting properly. - 2004 Chevrolet TrailBlazer

Your windshield and rear window has defrost outlets that exhaust right onto your front and rear window glass. Your side glass probably doesn't enjoy this luxury.

Hi there,

Page 104 of the user manual articulates the climate controls functions of the vehicle. Defrosters are identified as buttons 16 (front) and 15 (rear). Temperature control with buttons (6) down and 8 (up).


All Docs BMW 7 Series Owner Manuals

If it was me, the first thing I'd do is go check my fluid level in my radiator. I'd add fresh anti-freeze, if I hadn't done so in a year or more. Your defrosters won't work properly if you are too low on fluids in your radiator, OR your thermostat is malfunctioning. Replacing your thermostat might be a good job for a mechanic. Good luck.

Is there should be a fuse curcuit for the rear defrost there may be more than one device that runs on this curcuit check the fuse, then the switch, then check the element on the back window

i had a 2001 cirrus that did that i found that it was a vacum line for the defrost as for the rear window if the light is on in the buttonon the dash then you might want to see if the wire that goes to the defroster on the window are both hooked up

could be a thermostat problem if it is stuck open or none in engine. also check your water valve to see if it is working properly. Might need a system flush as sometimes the heater core will clog over time. as for the rear defroster, 3 things to check. first turn on rear defroster and check for voltage to window. if no voltage check fuse and switch.

best bet would be if its under warrenty, even if its not, take pictures of the window when it starts to defrost, and make sure you can see the spots that it is not defrosting. a cobalt i had worked on needed a new rear windshield to fix the problem. it may work but it doesnt work. could have a couple bad lines in the defroster, or it could have wiring issues. but pictures say a thousand words when you are trying to get something like that fixed.

I have had this same problem with my 2000 Sebring Convertible. I was told that the rear defrost is often a problem in convertibles and hatch-backs. My problem is very obvious though. When I turn the rear defrost on - the light does turn on (as if it was working), but the power does not get through. There are small 'clips' on each side of the window that hold the wires. After time and putting the top up and down, the clips can come off. My passenger side clip is currently hanging - very visible. Many mechanics are afraid to fuss with putting it back on for fear that they cause more damage than good. Look on the sides of the rear window and you may see the problem. Good luck.

The main cause for the rear window not working is a disconnected wire at either side of the defroster grid. You can see where the body harness connects to the rear glass.

The second most liekly cause are broken defroster grid wires.

I would suggest to you to obtain a 12 volt DC testlamp, and check for voltage as follows, at the rear defroster.

Hook the clamp of the testlamp up to a known good ground. The back door latch 'hoop' is great. Next, turn on the rear defroster, and place the point of the tip on the extreme side of the back window, on the grid. Does it the tester light up bright? If not, try the other side.

The light, moving across the grid, should get noticeably dimmer, if the grid is functioning properly. The light will go out when you encounter a broken grid wire..

Seems like you are not getting enough current to make it work properly. Check for bad connection, burnt connection, corroded connection etc. Maybe the contact to the relay is worn as well.