Finally got around to this this past weekend. PO had removed the blower resistor and purchased another for replacement, used, but not installed. Motor okay. Installed used replacement blower resistor acquired by previous owner. Fan blows constantly while key on, as with last resistor. Do I have another bad one? This is an MCC climate control system. Fan switch has no effect on the blower. Questions:

- Is it possible to test the resistor to see if it's good? If so, how would I accomplish that with my little digital multimeter?
- How do I eliminate the possibility that my climate control unit (switches, etc. in the center of the dash) is malfunctioning?

Really hope to resolve this, as AC season in the South is rapidly approaching. Speaking of which, compressor does not seem to be engaging.
- Insufficient charge and a low-pressure switch is preventing the compressor clutch from engaging?
- AC compressor relay bad?

Thanks for your help!
Jeff