Solved for now at least.
I read on this forum that one cause for a heater motor not working properly is debris gets into the squirrel cage. When I took the motor off and cleaned a few pine needles out of that area, the problem still existed when I put the motor back in.
I found that if I lightly tapped the motor body it would start up, but it was making an intermittent ticking noise. After a few days of this, it started coming on more slowly when I tapped it, gradually coming up to speed. I decided to buy a new motor, but I had some questions about the right part, so I took the motor out of the car again to check some features of the OEM fan motor for comparison to the aftermarket parts.
This time I also removed the motor body's silver bottom plate held on by two gold-colored screws (circled on photo). With the plate removed, about 2 tablespoons of copper dust, decomposed vegetation fluff, and spruce needles came out (21 years worth!) FYI, copper dust is toxic, so use proper personal protection.
Since the motor brushes are at the bottom of the motor, the armature at the brushes was trying to churn through all this crud.
When I put it back together it seemed to work normally again, but time will tell. Earlier posts have asked about how to remove the motor. Here are the steps... (If you just want to check for dirt in the motor itself, just do steps 1, 8, and 9.)
1. Remove glove box door by removing two phillips screws under the bottom edge of the door.
2. Remove the door's mounting plate by removing 4 phillips screws
3. Pull the plastic corrugated tube off the motor body
4. Loosen the hex head screws behind the two access doors shown in the photos. Loosening these a bit allows just enough flexing of the dash to work the fan from its housing.
5. Remove the 3 8mm hex screws holding the gold-colored base to the black motor housing
6. Lower the fan while pulling the loosened dash panel to the passenger side just enough to get the fan motor and squirrel cage out of the dash
7. Disconnect the wires' connector plug at the base of the motor or at the other end
Clean debris from the fan housing, and then
8. Remove the two gold covered screws from the silver base blate on the motor, and find where two soft plastic flaps (look like electrical tape) cover the spots where you can insert a flat screwdriver to pry the base plate off.
9. Tap the motor body, and the debris will fall out of the bottom of the motor. The photo shows how much came out on half of a paper towel!
P6183076Web720W.jpg 46.7K 76 downloads
Edited by BB's93LegacyL, 18 August 2014 - 10:29 PM.