Troubleshoot Fan Blower?

SkierDude · October 23, 2008

2001 GMC Sierra 1500 5.3l Z71 with A/C.

Heating/Cooling fan switch works at all levels, the blower makes a lot of noise but air volume is greatly reduced. I've seen several posts regarding resistors and replacing the blower. Can someone give basic instructions on how to pull apart the passenger side dash / glove box so that I can troubleshoot this and get the right replacement parts? I blew off troubleshooting this all summer, now it's 12 degrees in the morning and my defrost barely works.

Thanks!