How do you change the heater core in a 1999 Dodge Ram 1500 4 wheel drive?

Answer 1

You will need to remove the dash and HVAC housing to access the heater core.

Start with disconnecting the battery.

You will then need to recover the Freon from the ac system and drain the antifreeze.

Under the hood you will need special tools to disconnect the ac lines at the firewall, remove the heater hoses, remove the engine computer and remove four nuts that hold the HVAC housing.

Inside you will have to remove the trim on the sides of the windshield, trim at the base of the doors, remove the trim below the steering column, remove the steering column, remove the trim on top of the transmission tunnel, remove the airbag computer, remove screws across the top of the dash and on the sides, unplug numerous connectors and remove the dash. You can just lay it on top of the seats.

The HVAC housing is then held in with two more nuts.

Once you get it out you then remove the screws that hold the Heater core in place. If you want to replace the evaporator coil while you are there ( a good idea ) you need to remove the screws that hold the top cover on.

You reverse all steps to install.

Do not forget to fill the antifreeze and warm the engine up before driving.

You will also need access to an ac vacuum/refill machine to recharge the ac.