This morning was brisk, so I cranked the car up put the seat heaters in. A few minutes later I jumped in expecting to find a toasty seat only to find a cold uninviting seat. At first I thought the seat heater didn't work, but then felt the back start to warm up but not the butt. I figured the seat didn't heat up because my weight wasn't in it - which is smart I guess. However, has anyone had part of the seat heater fail? This is my first time using them so I have no idea what to expect.