heated seats

Sorry for putting this in TrailBlazer but i have an 02' Bravada with the memory,leather heated seats. Last night the drivers side seat heater stopped working. The indicator lights will not come on in the buttons of the arm rest and the seat will not heat by pressing the buttons. Now here's the strange part,when you turn on the heater in the passenger seat, they both heat up. Anybody know what's up with this? Again sorry, for posting here but there seems to be alot more information in this forum.