Cadillac Seville / Cadillac Eldorado Forum Discussion, 2003 sls heated seats in Past Cadillac Vehicle Discussion; They stopped working. Check fuses or what? Battery is new so that isn't the problem....
Turn the key On. Press a seat heater button and listen down low under the front seat apron. An intermittent click indicates the seat pad or back heater element has opened - the module is trying to close the circuit, but "sees" infinite resistance.
Otherwise, check the fuses - both underhood and under rear seat pad boxes, an d check the under-seat connectors to the heater modules.
There is a new design heater element in the field - dealer - and the least expensive install is to use a good upholstery shop if you doin';t attempt DIY.
Some have disassembled the seat and pads to find the element break, and then soldered a small jumper across the break, but that doesn't seem to last very long.