Maybe a fuse out? Which fuse is it? My light comes on in the heated seat switch but it wont heat. My pass side works just fine. Its a 2002 montero sport limited leather seats. ThanThanks for your help

 

The same fuse that powers the lights on the switches, powers the seat heaters as well, therefore, the fuse is good. What needs to be checked is the heating element in the seat. You're going to go to the seat and unhook the connector (3 wires) and check pin with your ohm meter (pins 1,3 on the wiring harness that goes into the seat) and see how much resistance you have, or if there is no resistance (no continuity), the heating element has failed. Also check pin 1 on the body harness side for ground by ohming that as well. If you have no continuity, you have no ground therefore, the seat heater won't work (ground 10 is a shared ground) The drivers door actuator/lock operates off the same ground, it is safe to assume if your door lock works, you have a good ground supply. FYI, there is also a safety element/thermostat that could have failed, not allowing the seat heater to work either. Let me know if you have any questions.