Power seats do not work when trying to use the switch located at the seat

2004 GMC SIERRA
210,000 MILES • 5.3L • 4WD • AUTOMATIC
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DAVIS.BARKER
  • MEMBER
  • 1 POST
If I press the driver 1 or driver 2 buttons on the door panel switch, then the seat will go all the way forward or all the way back. The Lumbar control does not work at all, neither does the recliner function. I tested the main harness under the seat with a test light and it appears that I have power at the source. I replaced the switch with a new one and it did not solve the problem. Please advise.
Oct 11, 2021 at 6:28 PM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

If you have power and the switch is new, that leaves us with a possible bad ground. If you look at the attached wiring schematic, it indicates the ground to be black in color. However, if the vehicle is a crew cab or not makes a difference in the location of the ground. The location is indicated in the schematic.

Do me a favor. Disconnect the switch. Next, check for continuity to ground via the black wire in the wiring harness connector.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

Let me know what you find.

Joe

See pics below. Also, I had to cut the schematic in half to make it readable. I did overlap them so you can follow from one to the next.
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Oct 11, 2021 at 9:00 PM