You've most likely got an open circuit in the seat. The blinking light is the way the computer "tells" you that there's a problem. My rig, a 2000, requires replacement of the entire cover whereas later models beginning with the 01 I think but maybe the 02 can be fixed by replacing just a slip-out/slip-in heating pad. Much less expensive. Of course, you can always get into the seat yourself with a meter and a soldering gun and likely fix the thing for the cost of your time.
Good Luck.