Mazda Repair: A/C blower problem, blower works, 1992 mazda b2200

Question
1992 Mazda B2200 pickup.  A/C worked great until today.  Blower doesn't work in lowest position, but A/C engaged.  In other 3 higher settings, blower works but A/C disengaged.  Is this a resistor problem?

Answer
This is a good question, but it is one that is difficult to answer. It could be a bad resistor. It is at least as likely that it's a bad switch. It could also be a bad relay. Then, there is the possibility that it is simply a wire that is grounding out somewhere. The only way that I know of to solve electrical problems like these is get out the test light and start tracking the problem down. I regret that I am unable to be more specific.