One problem related to rear window defogger has been reported for the 2000 GMC Sierra. The most recently reported issues are listed below.
The accelerator had stuck, the transmission slipped, the flaps on the fender and the door trim had fallen off, the back window leaked, the heat shield was believed to have caused a vibration in the dash-per service dealer, the coolant light stayed on, the a/c had to be repaired twice, and the rotors vibrated.