How to repair seat heater in 2002 Bonneville SSEI when relay is good and switch is good?

Question

I've already switched out these two components from the drivers' side and both are good. Would like to have schematic.

Answer 1

if u think about it this is easy, check the wires at the plug for power. if the seat is getting power to the heating element then the element is open and u will have to replace it.

Answer 2

This is snipped from GM service bulletin #01-08-50-012A which covers the 2002 Bonneville. Can't post the diagrams here so I hope you can use this.


The part # for the heater package in the Bonneville is
25730797


Some customers may comment that the front seat assembly heat function is not operating properly.

Cause
This condition may be due to a non-functioning heat element in the front heated seat cushion or back trim cover.

Correction
Determine if the front seat assembly heat element resistance values are within the specified range. Refer to the Diagnostic Procedure in this bulletin.
If the resistance values are NOT within the specified range, install a Front Seat Heater Package between the existing front seat trim cover factory heat elements and the seat cushion and back foam pads. Refer to the Front Seat Heater Package Installation Procedure in this bulletin.
Diagnostic Procedure
Remove the front seat assembly from the vehicle. Refer to Seat Replacement-Front Bucket/Split Bench in the Seats sub-section of the appropriate Service Manual for the removal procedure.
Disconnect the heated seat module harness gray, 6-way connector C2.
Measure the seat heat element total resistance between cavities A and C. Does the resistance measure less than 5 ohms?
If yes, go to Step 4.
If no, install the Front Seat Heater Package. Refer to the Front Seat Heater Package Installation Procedure in this bulletin.

Important
If the resistance is measured with the seat still warm, the resistance may vary outside of the specified range since the thermistor resistance varies with temperature.


Measure the thermistor resistance between cavities D and F. Does the resistance measure between 850 ohms and 11.50 K ohms?
If yes, the resistance values of the heat elements are within the specified range. To find the cause of the inoperative/cold heated seat, perform the standard diagnostic procedures in the appropriate Service Manual.
If no, install the Front Seat Heater Package. Refer to the Front Seat Heater Package Installation Procedure in this bulletin.