Heated seat problem

Driver's side seat heater stopped working recently on my '99 Tahoe. Passenger side still works fine. No blown fuses that I can see. I pulled the switch assembly out of the seat and using a test light found the following on the 3 wires going to the switch: Brown has power regardless of switch position, Pink/black has power when switch is in either low or high, and Blue/black has no power in any switch position. The seat does not warm on either the low or high switch positions.

Since that one wire has no power at all, could the switch be bad? Does anyone know of anything else to check? If not, I am guessing that the element is bad or a wire to it has been broken, so how does one go about disassembling the seat to get to those items? Any ideas or help will be appreciated.

I just had the exact same thing happen on my 2000 Z71, except the drivers' seat is fine, same power on the switch. I hope someone can give us an answer, it worked fine less than a month ago, and I am not really in the mood to pull the seat and replace the element! thanks for any and all help, Justin

Document ID# 341331
1999 Chevrolet/Geo Tahoe - 4WD

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Heated Seats Circuit Description
Heated Seat System
The heated seat system incorporates a heated seat switch, heated seat module, seat temperature sensor, heating elements in the seat cushion (front and rear) and heating elements in the seat back (front only). All the passengers seats (front and rear) have a seat belt switch that is used for an enable signal when the seat belt is buckled.

Front Heated Seat Description
The front Heated Seat Switches receive power, with the Ignition in the Run position, from the RR HVAC fuse in the I/P Fuse Block through CKT 341 (BRN). When the switch is placed in the LOW position, the ON signal is sent to the Heated Seat Module through CKT 1503 (PNK/BLK), and the HIGH/LOW Signal is sent through CKT 1505 (LT BLU/BLK) to the heated seat module. The low side of the Heated Seat Switch has approximately 275ohms of resistance, while the high side has approximately 310ohms of resistance. The Heated Seat Module receives battery voltage from the FRONT HEATED SEATS fuse, in the underhood fuse block, through CKT 1840 (ORN). With the heated seat switch on, battery voltage is sent from the module through CKT 1462 (LT BLU) to the Seat Cushion Element. Output is sent through CKT 1985 (PPL) to the Seat Back Element. Since the elements are connected in series, ground for both elements is provided through CKT 150 (BLK) to ground G202. The temperature sensors for the seats are located with the seat cushion element. The sensor monitors seat temperature and a varying resistance that is monitored at the Signal Enable, cavity E of the Heated Seat Module. The Heated Seat Module compares this signal to the HI/LO input to determine when to apply and shut off battery voltage to the heating elements. Temperature settings are maintained around:

37.5°C (98.5°F) for the LOW position.
42.5°C (107.5°F) for the HIGH position.
Both the Driver's and Passenger's, heated seats operate the same. However, the Passenger's seat needs seat belt buckled. When the seat belt is not buckled, the enable signal through CKT 182 (YEL) is grounded at the heated seat module and the system will not operate.

G.M. Heated Seats = headaches
We'll be working on these S.O.B.'s till spring!

I have the excact same problem with my 99 Tahoe 4WD with Heated Seats. The Drivers side just stopped working, both the back and seat element. Put a meter on the switch and its outputs looks fine. I also switched the 'module' with the working passenger side seat and the passenger seat continued to work fine while the driver side still failed to operate. So the module appears to be OK.

Anybody ever figure out what the problem with these things really are?

Thanks.

Heh, my 2000 Z71 has the same driver side problem. Passenger side works fine.

i have the same problem and had it diagnosed at local dealership...they indicated that i needed a new seat heater...quoted me at $372.48 plus labor...ouch...if anyone finds anything else out, let me know at [email protected]

I want to get this to the first page. This same problem just happened on my 98'. I was wondering if anyone had a quick or easy fix that is not $380.