My 04 Kia Rio rear defogger won't shut off, so far I have switched out the relay with the fan relay. Still won't shut off, I also tried another heater control panel. The light is always on and when I push the switch you can hear the relay cycle. The only way I can turn it off is to remove the fuse for the rear defog and the fuse for the mirror heater but the light still stays on. I'm thinking that I may have to wire a switch to each fuse slot.