I have a 1999 Park Avenue, and have a heated seat that doesn't work. The drivers side seat doesn't heat up when switched on. The lights on the switch fully cycle through off-lo-high. Is there a relay I should be looking at, or do the elements go bad in these?

Thanks for your help!

 

the most common problem i have seen with gm heated seats is that the heater "grid" becomes open. the grid is nothing more than one long wire. at some point in the wire it becomes burnt and then broken, resulting in an open circuit.

the repair is not hard, but you will need digital multi-meter, soldering and some auto upholstery experiance.

the first thing to do is to check the ohms on the lower heater grid, it should read no more than 5. i would like to tell you which wires you need to check but my diagram does not tell me the colors or show me a conector view. all i get is the cavity #'s and they are A & B.

if the reading is more than 5 ohms or open, the grid is likely at fault. if it is lower than 5 ohms, then check the seat back grid in the same manner.

be sure not to alter the thermal resistor on the grid! it should be hot-melt glued onto the grid wire. this controls the temp of the grid, and if altered can cause the grid to become overheated.

 

I have read a few things stating that I should also be checking the heated seat control module. Can anyone tell me where these are located, and if there's a procedure for diagnosing them?