For decades, I have leaned on Faxon for all my OEM original publications. I gave up on Chilton/Haynes/Motors/ad infinitum after frustration turned to anger too many times. I don't know when the seats your interested in first appeared, but Faxon has no Tahoe electrical books available after 2001. Here is the first year that I found electrical info on the Tahoe from the factory...
It's a little pricey, but it's GM original and so you could pretty much count on it being correct....
2001 GM CK Truck Wiring Diagram Original

Call Faxon and see if you can make a buy-back deal with them after you have the info out of the book and/or make copies.

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