blower switch - controls amount of air for heat, defroster & A/C

What is your question?

The switch has 5 positions: "off" "low" + + and "high" The "low" and the next position (+) result in NO air being blown by the fan - the next two (+) and "high" work just fine. The problem is that I cannot use the blower on the "low" or the next setting. The result is that there is TOO much air at the higher settings. What can be done to make this work on the lower settings - at a REASONABLE cost?