[Creative]

And I'am not totally sure but alot of GM's used resistors to control the fan speed and these are located right next to the fan (( for cooling reasons )) and some times they have been knowen to fail ... ((( they have four heavy gauge wires going to them ))) and you can usally pull them out with two screws and there's three coiled wire wound resistors and see if any are burnt out ....

And like I say this might not apply to this car but it does for alot of older GM products ......

Oh and the Hanes Maual doesn't help alot with the wireing or relays .... maybe go ask a dealer if you can take a quick peek at there service manual, most will let you if you have clean hands and buy there parts at some point in time .....