This 2006 Chevrolet Impala came in with the complaint that the rear window defroster does not work. The amber LED on the push button switch turned on and off as the switch was activated so I turned my focus to the rear window defroster relay and fuses. They are located in the underhood fuse box.
The rear window defroster / defogger relay in the picture below.
The rear window defroster 40 amp fuse. It is labeled as the BATT #3 fuse.
The heated mirror 10 amp fuse. It is labeled as the HTR MIR fuse. Since this car does have heated side mirrors it makes testing a little easier. The fuse should have power on it with the key on and the rear window defroster switch turned on. The relay should also click on and off with the switch command. Power at this fuse will indicate that the switch, relay and wiring in between are all okay. The 40 amp BATT 3 fuse can be removed and inspected to see if it is okay as well.
If everything tested good in the underhood fuse box the attention should turn to the passenger side kick panel. The rocker panel portion lifts up to release the retaining clips and then it can be pulled away from the pillar.
There is a large connector tucked in underneath the carpet. I am pointing to the damaged wire in the picture below. You may want to click on it to enlarge the picture.
With the connector pulled out you can see the heat damage on the under side of it.
I cut the purple wire on both sides of the harness connector and spliced in a bypass wire.
I did have to disconnect this harness from the interior fuse box in order to have enough room to work with the in line harness connector. The grey lever has to be lifted fully and then the connector can be wiggled free. It took a fair amount of twisting to get it to release.
The new wire connected to the purple wire on both sides of the in line connector.
I tucked everything back into position and re installed the plastic cover.
I installed a fused jumper wire into the circuit in the underhood fuse box and took an amp reading. Just a hair over 19 amps.
Another one fixed.