If the car did not come with heated seats when built then the wiring harness does not have the leads for the heated seats. Each wiring harness is custom built for the options ordered on the car. So you will need to run wires to the switches, fuse panel, and the seats. Also, did the seats come with the realys that are located under the seats? In any case the hardest part of the project is putting the heated cushions into the seats themselves, so if you already have them you are a good part of the way there.

 

Thanks for helping out RaceSX guys. I sold him the seats thinking that they would just plug in and work. I originally bought them for my Boxster (I had the heated seat option) so the harness looked like it would work just fine.