My 2005 Mazda 6S driver side heated seat turned on one day and there was an extremely very, very, hot spot that occurred at the rear right side of the seat. I think the seat almost started smoldering (smell). Anyway, I shut off the switch, trying the seat heater the next day. At this point, the seat 'does not' heat; however, the switch does light upo indicating the circuit is good to the switch and I'll assume to the seat heating coil. Checked all fuses and they're good. What I think happened, the heating coil where the really hot spot was felt, developed a high resistance; thus the very high heat being felt. Thereafter, I think that when it was turned on again, the heating coil 'opened' at that point. I assume I can check resistance of the seat coil when weather allows (Minnesota and very cold to work in garage). What I'm wondering is if anyone has ever replaced this heating coil in their seat. If so, do you have a source and P/N that can be ordered.