NHTSA recall 79V014000
Visibility › Defroster/defogger/hvac system › Heater core
Mack MC and 1 more
The defect
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.
The remedy
Dealer will replace the portion of the existing hose that IS closest to the accessory relay with an all-rubber hose.