Heater A/C control problem

I have a 1988 Oldsmobile Cutlass Ciera with about 130,000 miles. It has the V6 and is an automatic. A few months ago, I was having problems with the heater / A/C. It wasn't blowing out the correct selection. I discovered that the vacum hose was not connected and I reconnected it. Everything worked fine until about two weeks ago. The fan selection (low, medium, high) stopped working. The temperature and selection for where the heat / A/C comes out still works fine, but it will only blow out minimal amounts of air from the appropriate selection and temperature. Could it be the dash control, blower motor or something else? Please help, it is starting to get cold here and I need a more heat.