by Freon » Thu Dec 20, 2012 4:18 pm
Find where the draft motor plugs into the control board. Unplug it, have someone call for heat and you CAREFULLY test the voltage at the control board. If you see 120 volts at the plug on the control board for more than the 5 to 6 seconds then the draft motor could be the problem. However if the voltage at the board drops to zero then the board may be the problem. Check the board for cold solder joints and especially around the relay that switches the 120 volts to the inducer motor