The blower motor on my gas furnace has an intermittent issue, it rarely turns on. Everything else turns on in proper sequence (vent, flame). I thought it was the capacitor because after removing and testing I reattached it and the blower motor engaged as expected. The next time the furnace turned on, the blower again refused to move. I replaced the capacitor, the blower engaged again, but with the same result; after the first time the blower doesn't turn on anymore. What should I be looking at next?