I have a comfortmaker hvac system. The heat works just fine, however the air quit suddenly the other day. The compressor comes on along with compressor fan outside, but the blower inside the furnace will not come on. When I tried the fan on only the blower still would not come on. so I tried another thermostat and got the same result. The control module in the furnace is The General 90, model 50A50-110. I am thinking it is probably bad, any one seen this before? The system is about 15 years old.