TRUCK HAD BEEN SITTING OVERNIGHT. WOKE UP TO 3RD BRAKE LIGHT ON. OPENED CAB DOOR, SMELLED LIKE SMOKE AND CHECK ENGINE LIGHT ON, WOULD NOT TURN OVER. POP HOOD AND THE FUSE BOX AND WIRING HARNESS HAD BEEN ON FIRE, WERE COMPLETELY MELTED. INSURANCE COMPANY WON'T COVER BECAUSE THERE WAS NOT SUBSTANTIAL PROOF OF FIRE, AND COULD NOT FIND SOURCE. FILED A FORMAL COMPLAINT WITH GM AFTER THE DEALERSHIP TOLD US THE WIRING HARNESS HAD BEEN DISCONTINUED (ON A 7 YEAR OLD TRUCK). GM WON'T DO ANYTHING BECAUSE THEY CANNOT FIND THE SOURCE, AND THEY HAVE YET TO ACKNOWLEDGE THAT THEY DISCONTINUED A PART. WE HAVE NO WAY OF FIXING THIS TRUCK.