2004 XC70 125K. Bought it at 71K. Last owner must have been a big guy! Seat well worn. This morning I started it and got out for a minute, came back and smoke was coming out of a worn hole on the side of the seat! Shut it off and poked my finger in to stop and no more smoke. I pulled out fuze #7. Anyone ever hear of this problem?

 

Seat worn enough to put a hole in the seat cover likely means that the seat foam is damaged as well which means the seat heater wires are likely damaged enough to short out causing a hot spot and smoke.

Have seen a SAAB seat heater do this (hot spot) without damage to the seat cover. Burned the seat cover and the customers pants and leg.

 

Ouch. Thank you for the info! Have a Great Christmas!