TRUCK PARKED AFTER LUNCH - SPONTANEOUSLY IGNITED IN PARKING LOT - ORIGIN IN LEFT REAR OF ENGINE COMPARTMENT - CRUISE CONTROL DEACTIVATION SWITCH RECOVERED - SWITCH HEAD EXAMINED WITH X-RAYS - ONE CONTACT IN TACT WHILE THE OTHER IS SPLATTERED AND MELTED - INDICATES ELECTRICAL ARCING ACTIVITY INSIDE SWITCH - FUSE # 13 BLOWN. *NM