Part 15: Hold Your Temper...ature

With the box on a workbench, remove the clips that hold the two halves together by grabbing the tab on each clip and pulling.

With the box separated, you can see our problem heater core. The heater core is fastened to the box with four screws. Remove the four screws, the heater core, and...

...in our case, this stuff fell out. I have no idea how air passed through the box for the previous owner. Even the squirrel-cage fan was packed full.

With the two halves separated, you can see the flap (or door) that regulates the temperature of the cabin air by mixing the heated air with fresh air from outside.

The blower motor is secured to the box by these little snap collars that slide over the motor studs and secure the motor and spacers. The spacers are required to give the support to the box while spacing it out away from the insulation on the inside of the firewall. Remove the collars and spacers, and slide the motor out.

Now, with everything apart, clean the box with warm, soapy water. Be careful not to damage the edges by dropping it (guess how we figured that out). Also remove all the old foam from the flappers and clean them up with a wire wheel or a bead-blast cabinet. New foam is available at hardware stores and upholstery shops. Using contact cement, put the new foam where the old was removed.

Remove the motor plate by carefully drilling the POP rivets out, sandblasting it, and reattaching it with new POP rivets.

Reinstall the flapper doors to their proper locations.

Use the old cardboard backer as a template on the new cardboard. We got our new cardboard from an upholstery shop, because it's water-resistant. After making your new backer, reinstall it to the box using the clips.