I have an '03 Silverado K3500. This past summer, the blower motor quit working on (5) high. The other 4 speeds all work fine, just the high speed is inop. It wasn't an issue in the summer, but now it is cold and I need a little more heat in the cab. Is the resistor the most likely cause of this or am I in need of a new switch? If it is the resistor, where is it and is it a pain to get to? Is GM only the best option or is the aftermarket a viable parts solution? Any and all help will be appreciated. My frozen feet thank you!!