2002 GMC Sierra radio lights and fan speed switch

Hi sent4lams. I can help with the radio lights. They are very tiny incandescent bulbs that must be soldered in place. Depending on the model, they are either 5, 8, or 10 volt bulbs. This pertains to the radios that are about 3 3/4" tall. If you have the newer, taller style, removing that radio might require a visit to the dealer to have it reprogrammed when you reinstall it.

As for your fan, look for a relay that only turns on for the highest speed. I can't say for sure but I think it's under the hood near the passenger side hinge. That's from memory of older trucks. Also look in the relay / fuse box under the hood.

Caradiodoc