the heating element under the seats does burn out after a while. Im just about to replace the heating device in my 960. The parts are available if you want to have it done by an independent shop.

Jim

Excellent advice from others on this topic. Here is some additional info:

If it is too warm for the thermostat to turn the heating elements on, a bag of frozen vegetables will cool the seat cushion niceley. Then proceed with troubleshooting.

The 240 repair manual published by Bentley describes the troubleshooting and repair proceedures (search for Bentley on amazon.com or your favorite bookseller).

My brother and I fixed his seat warmer last week. The problem was the connector had come off of the thermostat. We replaced the connector just to be safe, even though it wasn't really necessary, becuase I had one of the correct size. It is a standard quick disconnect, available at Radio Shack.

I have an 86 model and have found that the wires to the button type thermostat are fragile. They break from it after a lot of sitting down on them.

You can disconnect them under the seat and ohmmeter the element for resistance only if the temperature is below 60 degrees. You can pull the plastic holder and wires out from under the cover from the open ends where the back meets the bottom. I have trimed the wires and solderd them back on. Allow slack to the thermostat helps for it to last longer but it is a bad design for the most part.

I have seen where IPD sells replacement items but don't know what the quality is or if the design is better.

David gave you some good advise. When you flip the seat heater switch, you should be able to hear the relay click under the seat. I will just add to check the thermal switch in the seat that regulates the temperature and turns the elements on and off.

There is temp control relay under each seat. Also check for continuity of the heater elements. You really need a circuit diagram to do this.