Rear window defroster does not work

I don't think its supposed to clear off snow, only fog or condensation. Try to remove the snow, and see if it will clear the fog. The wires connecting the defroster to the window should be on the side of the window, or behind a cover somewhere. Look for something like this:

OR:

Do you have 12 volts to the rear window grid at the grid connector, check and make sure it is attached to the window, it is the single biggest reason for failure.

Using a 12 volt test lamp, check for power at the connection to the grid. If no power there, check fuses, and switch. If there is power at the connection, look closely for a break in the continuity of the grid. Usually right near where the wires connect. If broken, parts stores can fix you up with a conductive glue. Common problem, and the glue is cheap, and works great. Good luck!

Check the switch. Check for 12 volts going into the switch. You should have 12 volts coming out of the switch when the brake pedal is depressed.

Check to see that the wires that connect to the rear window are indeed intact...then you will need to look at the lines in the window to be sure none of then are broken...to go further, you will need a voltmeter...hook up the voltmeter across the two leads that connect to the window and turn on the system to see if it delivers 12 volts to the window...if so then the connections are either bad or the wires inside the glass are open

There is a connector going to rear defrost on the rear window. Disconnect this and check for voltage with defrost on. If this is good, check resistance for the connection to window. This will tell you if the electrical is working or the element is bad for the window if there is a open reading on multimeter.

Hello.
The rear defroster isn't affected by a/c operation.
The most common issue I see in my shop is the rear grid damaged.
The wire you see in the rear glass is a resistor type conductor which builds heat as electricity passes through it. If the grid wires get scratched it is like a broken wire and will not build up heat as there is an interruption in the flow.
First thing is verify your fuses are good and the indicator light comes on when the switch is depressed.If they are OK proceed to the next check.
If you look carefully at each side of the glass there is a wire connected to the grid. If these have come loose or become corroded that is where your problem has most likely occurred.
To test it a 12 volt test light or a multimeter should light or read battery voltage applied at each side of the glass grid.
If indeed the grid is damaged there is a repair kit available to fill in the gap at your local auto supplier.
Hope this helps you with your repair.

this problem is caused by the body control module, the dealer will have to test the functuion of this module.

If you have a 12 volt test lamp, try this: Turn on the rear defroster. Attach the clamp to a good ground point; the door latch hoop is good)...Now, touch the test lamp to the extreme left and extreme right sides of the grids, on the inside of the glass. If the light does not light in either place, you probably either have a bad defroster relay, or the wires coming to the rear grids is off. Please feel free to get back to me with the results of your test.

there may be a defrost window/ liftgate fuse under dash or in the engine compartment check that first/ you can also check the plug in for the defroster it just pull out and clean with steel wool/ after that if that does not work then the actuall switch is bad switch the button that is/ if you have questions let me know Please rate my response thank you very much