Contributed by Mathew Banack
Maintained by Josh W  (josh_w@sprynet.com)

Changed my heater blower motor on my 81 non-A/C caddy on the weekend. It came out via the outside cowl... it was tight, Even with trial and error time, it was in and out and done in an hour and fifteen minutes. Here's what happened....

1. Before opening hood, remove windshield wipers arms, and the acorn nuts from the stems. Each wiper arm stem that sticks through the cowl has two stainless washers that sandwich a rubber grommet and are held tight by those acorn nuts. One washer from each stem should come off from the top-side now, and one washer from each stem should come out from the under-side in step three. In step three, get that washer off as soon as you can, so that as you wiggle the assembly around getting it out, you don't drop and lose that washer.

2. Open the hood, and remove the plastic leaf/drip-catcher thing from the cowl area by gently prying open the clips on the back edge, and removing the rubber molding from the front edge. If this leaf/drip catcher is all cracked up and brittle and missing pieces, replace it, because it keeps the chunks out of the ventilation, and keeps the water off the heater motor, which may be why your heater motor is fried.

3. Remove the windshield wiper assembly. There should be one bolt (10 mm head) just forward of the wiper motor. Undo the wiring plug. Its quite a trick to wiggle it this way and that to get it out. Make sure to keep track of those stainless steel washers, one on each stem, if the washers drop down into the heater box, they can be quite ugly to retrieve. The speedo-cable will be trying to get in the way, you should be able to wiggle it down out of the way.

4. Remove the four (8mm head) screws that hold the heater unit up underneath the underside of the cowl. Once those four screws are out, the whole heater assembly will only drop down about a half inch, but you need that half inch to get the blower out. There is a metal washer and rubber sealing washer under each of the screws. Take those washers off and set them aside; during reassembly, getting the holes aligned and the screws started is easier without the washers, then when all four screws are in and close to snugged-up, take them out one-at-a-time and put the washers under each.

5. There's a spring steel clip that holds a porcelain sleeve and the fan-speed resistor, unclip it, and unplug the wires from the brush-holder on the end of the blower motor. Lay the wiring aside towards the drivers side. The wires un-plug with male/female, so there's only one way to plug them back in so there should be no need to mark them.

6. Remove the one phillips-head screw that holds the resistor spring clip and the front of the blower motor. Remove the circular rubber grommet under the spring clip that holds the motor.

7. The motor should now come up a bit, slide forward a bit, and then come up and out the rest of the way. There are two plastic tangs on the back of the blower motor that slip into a slot on the back of the heater box; on each of the tangs is a rubber mount. As soon as the motor comes up out of the mounting position, reach around back of it and remove those two rubber mounts so they don't fall down into the abyss of the heater box.

8. Jiggle and wiggle and turn the blower motor this way and that to get it out of the heater box. I found that with the motor-end (versus the fan end) of the blower assembly down, I could take the blower towards the passenger side of the cowl all the way to the end, and rotate it up and out past the hood hinge.

9. Before putting the foam rubber seal on the new blower motor, go through the sequence of getting the blower in past the hood hinge, along the cowl and into position in the heater box. Best not to put that foam seal on until after you go through the trial and error get the route back in down pat.

10. Of course, that foam rubber adhesive seal holding the blower motor into the heater box tore itself into about six pieces on the way out. When you scavenged the "new" blower from a dead car, the foam seal probably screwed up as well. I used a piece of 1/2" wide by 3/16" thick (cut lengthwise to 1/4" wide) self adhesive foam weatherstrip. The foam you need to go around the contours of the blower is 1/4" wide x 27" long, so you'll need like 14" of weatherstrip. That self adhesive weatherstrip sticks best to a clean surface on the new blower.

11. Remove all the chunks of the old foam seal from the seal surface inside the heater box. This is a good time to look down at the top of the heater core, if theres chunks of leaves and crud in there, gently get in there with the shop vac and clean it out.

12. With the weatherstrip on the new blower, put it inside the cowl, and move it along and up and around into position in the heater box. Just before dropping it down, and back and into position, reach around back of the blower and put those two rubber mounts back onto those plastic tangs on the back of the blower. Down a bit, slide the tangs back into the slot, and pop the blower down into position. Replace the rubber grommet on the front mount, and the spring-clip and phillips screw that hold the resistor. Reconnect the motor, and put the resistor into its clip. Now is a good time to test things, go inside the car and turn the key on and test the blower in three speeds. If your new motor is squeaky, now is a good time to find out.

13. The toughest part of this job is getting the heater box back up into position to start those four screws that hold it to the cowl. You've got gravity and all of Murphy's laws working against you. Easiest to get a buddy to help you by lifting the whole heater box up from inside the car. Or, you can roll up a pair of coveralls or something, and jam it underneath the heater box to hold it up while you put the screws in. I clipped a pair of vise grips on the lip of the heater box sticking up into the cowl area, and then used a pry-bar under the nose of the vise-grip to lift the heater box up to get the screws started. As mentioned before, its easiest to leave the metal washer and rubber sealing washer off the screws until after you have them good and started. Then, remove the screws one-at-a-time to put the washers on.

14. Replace the wiper assembly. Reconnect the plug to the wiper motor. Test that the wipers work.

15. Replace the plastic leaf/drip-catcher thing.