How to Replace the Heater Core in a Ford Mustangby Contributor
Replacing a Mustang's heater core isn't an easy task. The core is located behind the instrument panel, which you must remove from the inside to reach the core. This job requires at least two people and is best left in an expert's hands, if at all possible.
Drain the Mustang's cooling system and recover the air conditioner refrigerant, if it's equipped. Disconnect the cable from the negative battery cable. Disable the car's air bag system.
Remove the floor console, door scuff plates, lower A-pillar trim panels and the instrument cluster. Secure the steering wheel into its straight-ahead position and disconnect the steering shaft-to-column pinch bolt.
Begin disconnecting the instrument panel. Start with the left side bulkhead connector, and then remove the panel support bolt, antenna inline connector, right side electrical connectors, center support screws and support bolts.
Disconnect the panel cowl top bracket nut through the cluster opening. Remove the lower panel support bolts, end panels and upper support bolts. You can now take off the instrument panel with another person's help.
Clamp off and disconnect the heater hoses attached to the heater core. Disconnect the evaporator core nuts and the fitting. Remove the heater core housing nuts on the dash panel and the antenna cable from the housing.
Loosen the inside evaporator housing nuts and extract the heater core with the evaporator housing.
Install the new heater core with the evaporator housing and tighten the housing nuts. Reconnect the antenna cable, heater core housing nuts, evaporator core nuts and heater hoses.
Reinstall the instrument panel with your assistant's help. Reconnect every support bolt, panel and connector in the reverse order of removal.
Connect the steering shaft-to-column pinch bolt. Reinstall the instrument cluster, lower A-pillar trim panels, door scuff plates and floor console. Reconnect and enable the air bag system.
Attach the negative battery cable. Refill the cooling system and recharge the air conditioning system. Start the Ford Mustang's engine and check for any leaks in the system.
- If your Ford Mustang is equipped with R-12 air conditioner refrigerant, then you can't recover or recharge the air conditioning system as mandated by the Environmental Protective Agency. Only EPA-certified technicians can perform these tasks, so you may have to take it to a professional even if you preferred to do the job yourself.