One problem related to alternator/generator/regulator has been reported for the 2002 GMC Envoy. The most recently reported issues are listed below.
After starting the car, a burning smell entered the cabin. Noticed the volt gauge was only reading about 9 volts instead of the usual 14. Took car in for check up, and found the alternator had failed. After removing alternator found that the pulley could not be turned as the unit had seized up. This also damaged the tensioner which had to be replaced along with the serpentine belt. The mechanic indicated that we were very close to having a fire.