INERTIA SWITCH BELOW PASSENGER SIDE DASH BOARD DEFECTIVE. HAD TO BE RESET FREQUENTLY (NO LESS THAN ONCE WEEKLY FOR 3 YEARS), UNTIL IT CAUSED SMALL ELECTRICAL FIRE BENEATH PASSENGER'S FEET. ENGINE STOPPED WHILE DRIVING 65MPH ON I-17 IN CENTRAL PHOENIX. HEAVY TRAFFIC CAUSED DIFFICULTY MANEUVERING ACROSS 3 LANES TO THE SHOULDER OF THE ROAD. AN ARIZONA DEPARTMENT OF PUBLIC SAFETY OFFICER WAS NEAR BY, AND ASSISTED TO PREVENT A COLLISION. PASSENGER PUT OUT THE FIRE WITH ONBOARD FIRE EXTINGUISHER. AFTER REPLACING THE INERTIA SWITCH (WHICH WAS BADLY DAMAGED BY FIRE), THERE HAVE BEEN NO FURTHER PROBLEMS. *TR