If you have a switch mounted on the rear of your console, your car is at least wired for rear heated seats. The circuit is fairly simple: there is a fuse, a relay, the switch, 2 thermal/circuit breakers (one in each rear seat), and 4 heater pads (2 each cushion and backrest).
When you operate the switch, an LED in the switch should turn on (this is separate from the light that comes on with your headlights). If it does, this means the fuse, relay, and switch are all OK, and the problem lies in wiring to the seats, the breakers, or the heater pads. If the LED does not turn on, the problem lies between the battery and switch. I have a circuit diagram with wire colors and component locations if you feel capable of "troubleshooting".