Yesterday I checked out a Carrier no blower complaint. OD unit will start. Inputs from T/stat correct. But no ID fan. Model is a Carrier FC4DNF030. The blower motor has only 2 'hot leads', a common, and a ground. (all voltages correct) The last single lead goes to a simple board which has a plug in for the T/stat inputs and 24 VAC supply voltage. The 'output' for this board goes to the ECM and always reads 24VAC - even with no call for cooling or Fan 'On.' I have a TecMate which is useless in this case. Can you tell me what I am missing? Or really what to do! ( I know your thinking get another profession.) Thanks!