Well, the problem was, indeed, the booster motor. I got a replacement assembly, installed it, and the furnace works again.

Terry

I have a Coleman DGAA056BDTA furnace. Symptoms are as follows: Thermostat calls for heat, I hear humming in the booster/combustion motor but it does not spin. I read 120vac going into the two terminals of the motor. After opening the small door and manually spinning the fan blade, it still does not ...