Driving along, lost gauges, radio, elec.windows. Stopped to check, relay or solenoid noise under hood when key is moved from off to on position. Engine starts no problem. After a lengthy cool down period, everything came back. Happened twice now. Checked owners manual for possible answer and found nothing specifically related to what was going on. Have been replacing control modules on a regular basis. Headlamp and door lock specifically. 265000 miles on an 02 Envoy. Any ideas ??? Have a code scanner but was not with me when failure occurred. Love the new home page. Thanks, Terry