Rear defrost dont work on my 2006 chevy impala. Found relay but has no fuse. all fuses under hood are good and the ones on passinger side kick panel are good. light lites up on switch but no power at rear conections.

On my 2012 Chev Impala the fuse box in the eng compartment has a vacuum pump relay where you are saying the fuel pump relay is

Check the fuses first. One located under the hood and one under the dash or left(driver side) kick panel. Also if fan works on a higher setting then the switch is bad and needs replaced

check the fuses the fuse for this can be found in your owners manual. if the fuse is good and the lite for the rear defrost lites up the rear heater strips on your rear window may be bad the only repair for that would be having the rear window replaced

ck relay under hood for click when defog button is pushed,if this relay clicks switch and relay should be ok,just found same problem with mine,remove right kick panel where the little fuse box is located and large connector under it i seperated and found burned connector,cut wires on both sides and ran jumper wire,make sure to use proper gauge wire,now mine works good luck

there is a connector that plugs into the light that should be looked at. is there any water leaks anywhere. there were problems with water leaks on some malibu models around the tail lights. pell open the inside covers and get to the tail light to inspect for this. also check those bulbs just in case they did go bad. any condensation in the light? not sure if the Impala has a single fuse for both tail light or one for each but you should check fuse box under dash and under the hood. good luck

First i would check the fuses you have two fuse boxes one on the inside located by the left foot of the driver or the passengers right foot, and the 2nd is located under the hood i dont think it will be under the hood. Check with your owners manual for what fuses do what. if the fuses check out. i would move to the rear of the glass. you will have 2 plugs on either side of the glass you can test these with a voltage meter or a 12volt test light one side is a ground and one side is power what may have happen is on of the defroster strips has worn off and its not completing the circuit. Auto parts store sale a special kind of conducting paste that you can apply right to the glass and complete your circuit. If you think everything is good at the back glass, or you think the problem is not there.
Also there should be a relay maybe under the hood that is more like a timer for this feature there could be a problem there relays aren't very expensive. Good luck

they have a fuse and a rely make sure the wire end is on the conector on the window

Ok, locate the relay panel (probably inder the hood) and find the relay that controls the headlamps. With your headlight switch "on", pull the relay and see if your getting a hot current to the connectors in the relay panel. If it's hot, replace the relay. If no current, it's probably your headlight switch.

check the wiring from the tailights back to the fuse panel, it sounds like an open connection. if i recall correctly check under the dash on the drivers side near the fuse panel for a bunch of wires in a bundle and look carefully for a wire or two that are cut/shorted/or seperated, you can also check under the drivers side kick panel by the hood release.

I don't know about the rear defrost, but there are 2 fuse boxes inside the car. Just inside the doors on the far sides of the dash. The covers sit between the dash and the doors. There are holes to stick your fingers in, and pull the covers off.

The fan issue, may be different then the prob. I had, I didn't have speed 1 or 2 on mine.
I don't remeber what the part is called, but it's some resistor board deal, that sits up under the dash on the Pass. side, right up against the firewall, it's a pain to get the new one in, once the old one is out though, so be careful not to crack the board. Ask a dealer, they will know what it is. I think it costed me like $30.
I hope that helps.