Blower motor woes

[motorcritter]

['71 C10 LB, 402, TH400, bunch of Cheyenne options- w/ factory A/C.

The blower only worked on high speed, and I didn't care, as it was warm out (A/C inop- locked-up compressor). Then it got colder, and it was OK, until the blower quit blowing on any speed. So, the fuse is good, it's got power. The motor is good, and the GM guys must have studied at Benz or BMW, so they could make a nice, challenging HVAC system to work on. Anyway, the blower relay had some corrosion inside it (of course I opened it!), but it cleaned up easily, and worked when powered up. I put an extra ground lead on the motor, also. The switch cleaned up easily, also, and worked properly- juice going where it was directed to. The wiring also had continuity (thanks to whoever put up the wiring diagram elsewhere on the board). I pulled the center section out, to access the resistor (gotta be it, right), and it had a small scorched part where one coil touched the bracket at some point. I cleaned it up and rearranged the coils, and they both had continuity and different resistance values. But- the big ol' but, when everything is snapped together- I still have only high speed! At one point, when going through the components I had all three speeds. When I thought- 'Ah-ha, button it up!', I was back to single speed.

Do I need an exorcist, or did Delco-Remy have Joe Lucas or Robert Bosch building this truck?
Any suggestions would be appreciated. And, yes, I cleaned all the connectors and replaced stff that was nappy. I even used my genuine Honda dielectric grease on the switch when I went through it.