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Recall campaign79V014000

Recall 79V014000: 1978 Mack MR

Visibility › Defroster/defogger/hvac system › Heater core
Report received
Jan 9, 1979
Manufacturer
Mack trucks, incorporated
Potentially affected
358vehicles
Model years
1978

Check your own vehicle. A recall applies only to vehicles within the affected build range. Enter your VIN at nhtsa.gov/recalls. Recall repairs are free at a franchised dealer.

What NHTSA recorded

A deficiency in the routing of the heater duct hose could allow the hose to rest against a terminal post of the accessory relay. Vibration will eventually cause the terminal post to penetrate the hose fabric and short circuit the wire reinforcement and overload the circuit.

Remedy

Dealer will replace the portion of the existing hose that is closest to the accessory relay with an all-rubber hose.

Affected model years

Pages for each model year show complaints, parts, mileage and other recalls.

About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 28, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.