Does the heater control between the two front seats have a light? Also does the a/c controls in the console have lights? What is the probable cause if both seat heaters don't work?
I can't remember about the lights, easiest thing is to just look under the dash and see if the AC and heater controls have wiring for lights. If the seat heaters aren't working, it could be a number of things: 1. Seats replaced with non-heater versions. 2. Fuse blown. 3. Relay blown. 4. Seats not connected to heater circuit. 5. Seat heater elements damaged. 6. Heater switch burnt out. There is no way to tell without getting in there with a 12V tester or a multimeter.
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