Hi Thanks for the add-on to the group bought a 2010 Prius a few months ago but the rear defogger is not working My friend who is decent with electrics in a car can't find the fuses for the car does anyone know the exact location and what number they are Thanks
There is a fuse box under the hood on the car's left side, and a smaller one under the instrument panel above the driver's knees. Do the mirror heaters work? They should come on at the same time as the rear defogger. That might tell you if the problem is just with the rear or with the controls. It's not so easy to tell if they are working, as they don't get super hot to feel by touch. But if you know someone with a thermal imager, that's easy, you'll see the zigzaggy heat wire glowing orange behind the mirror. (Just make sure there isn't something hot behind you; they are mirrors, after all.) The mirror heaters have their own fuse, MIR HTR (10 amps) in the underhood fuse box. The rear window doesn't get a fuse of its own; it's directly handled (and current limited) by the long white integration relay in the underhood fuse box, which also controls a bunch of other things. There is a 40 amp "P/I 2" fuse supplying it, but loss of that fuse would also lose you things like low-beam headlights and the horn. With a scan tool like Techstream that can show you the data list and offer active tests, you can see whether the A/C amplifier 'thinks' the defogger should be on when you push the switch, or you can command the defogger on from the scan tool, disregarding the switch. That can be helpful for spotting problems with the controls.
