Defroster/defogger/hvac system: fan/motorRecall 81V-157 · Mack vehicles
MACK TRUCKS, INCORPORATED recall 81V-157 covers 4,920 Mack vehicles for a defroster/defogger/hvac system: fan/motor problem, reported to NHTSA on December 29, 1981.
Source: NHTSA recall 81V157000 and manufacturer quarterly reports. Started by the manufacturer.
The problem
WHEN THE IGNITION KEY IS IN THE "ON" POSITION AND THE HEATER IS OPERATING AT THE "LOW" OR "MEDIUM" SETTING, THE HEATER SWITCH WIRING WILL OVERLOAD IN THE EVENT THE HEATER MOTOR SEIZES.
The fix
A SPEED VARIATION RESISTANCE UNIT AND AN ELECTRIC MOTOR MOISTURE PROTECTION CAP WILL BE INSTALLED WITHOUT CHARGE.
VEHICLE DESCRIPTION: TRUCKS.SYSTEM: HEATING; CAB HEATER MOTOR, ELECTRICAL SWITCH.CONSEQUENCES OF DEFECT: IF THE VEHICLE IS STANDING STILL (PARKED OR STOPPED INTRAFFIC) HEAT GENERATED BY THE OVERLOAD MAY MELT AND IGNITE THE SURROUNDINGPLASTIC HOUSING AND WIRE COVERING. A FIRE COULD SPREAD QUICKLY THROUGHOUT THECAB, CAUSING SERIOUS INJURY TO VEHICLE OCCUPANTS.NOTE: OWNER IS ADVISED TO MAKE SURE HEATER/DEFROSTER FAN MOTOR IS FUNCTIONALBEFORE USING CAB HEATER PRIOR TO REPAIR. HEATER/DEFROSTER BLOWER SHOULD NOT BEUSED IN "LOW" OR "MEDIUM" SPEEDS WHILE THE VEHICLE IS STOPPED OR ENGINE ISIDLING.
Recall repairs are free. Confirm whether this recall is open on your vehicle by entering its VIN at nhtsa.gov/recalls.
Vehicles in this recall
Built from September 1, 1979 to August 1, 1981. Not every vehicle in these model years is included; check by VIN.