i have prius 2004 yesterday the rear defroster stopped and not working while the key on steering wheel and the yallow light indicator works very well and mirror defroster also working well, this case it become yesterday but before that it was working as usual.
Two main possibilities here:- (1) The fuse in the box under the hood is blown, worth checking but there should be some other reason for this happening. (2) The heating element on the rear screen is damaged, Usually broken (scratched) by something carried in the boot. This can be repaired with a kit available at motoring stores. If you can use a volt meter both can be checked out without difficulty. John (Britprius).
The Rear Defrost stopped working on my 2005 with 240K this fall 2016. My problem turned out to be the connection on the upper rear door glass towards the bottom corner on the passenger, US Right, side the terminal overheated and became disconnected. It is under the black trim between the top and bottom sections on the right when standing at the back facing forward. I cut off the damaged female spade connector and crimped on a new connector adding some heat shrink tubing and electrical tape to replace the insulation I removed to get at the wire. It restored operation of the rear defroster so call it solved for now. Plan is to run it up to 300K and have Toyota change the Odometer Cluster. Got to have goals!!! daveatm14
Original plan was to solder the new terminal to the wire but it was raining on and off today so it was wet, overcast and chilly, low 50s F, under my shade tree with no garage (and no leaves in the oaks) in Missouri in late November with the wind blowing so I did not string the extension cord for the soldering iron and heat gun. Probably should have because I had to tarp off the back end to block the wind enough to shrink the tubing with the mini Bic. Had fun and got it done for now dog and I went for some errands and confirmed restored operation for now. If it fails again before 300K I know where to look first. <Big Grin> Do you think a Toyota dealer would have soldered on a new terminal? Probably would have wanted a new wiring harness. HaHahaaa. Thanks to all that support this site and DIY. Roll On!!! I do appreciate the advice.