When the vehicles are manufactured, different wiring harnesses are used. Also, the Grand Prix will not have the power supply or control module for it.
I won't say it couldn't be done, but it will take a lot of work. What I've done is attach the wiring schematic for the heated seat circuit in a 2002 Grand Prix. Take a look through it and see if it is something you want to perform.
Note: I cut the original wiring schematic in two so it is easier to read. I did overlap the two pics so you can follow them.
Let me know if you have other questions.
Take care and God Bless,
Images (Click to enlarge)
Wednesday, February 24th, 2021 AT 8:50 PM