Mopar MB939999 Core Heater

Disconnect the battery negative lead and set the heater temperature control to HOT. Drain the cooling system and then, working inside the car, remove the centre console and the parcels shelf. The now exposed centre ventilator duct and the windscreen demister duct should also be removed, along with the instrument panel trims. Disconnect the control cables from the heater and the heater hoses from the engine. The heater wiring at the multi-pin plug should also be disconnected. Remove the two upper and one lower heater mounting bolts and nut and remove the heater from the car interior. As the heater is withdrawn, make sure that the heater hoses and the bulkhead grommet are drawn through at the same time. Avoid spilling coolant which may be in the heater, on the carpets. If the heater matrix is leaking, it must be removed from the casing and either repaired professionally or a new or reconditioned unit obtained. Refitting is a reversal of removal but adjust the control cables. Refill the cooling system on completion.

The heater unit is mounted centrally behind the facia panel within the car. The heater matrix uses coolant from the engine cooling system. An electric booster motor and fan increase the air flow when the car is stationary or moving slowly. Fresh air for the heater enters through the grille immediately below the windscreen. Air flow can be regulated and directed by means of the levers and knob on the control panel to cover all requirements. These include temperature level, the particular outlet from which the air is to be ejected and whether fresh or recirculated air is desired.