Carrier product 58pAV090 model # 58PAVO90-14 Series 161. Main blower needed cleaning bad and I did so. Now it appears that it won't cycle back on .At times the motor runs perfectly from start to finish and at both the cool and the heat cycling times.But not both. If I tape the switch and help the blower sometimes it goes.. sometimes not and it just sits and hums.It sometimes won't take off even when I help turn the cage to help it to go .I have been playing this game for 15 hours Michigan .Help.. How does one verify a bad motor? Can one work perfectly and then not take off properly and then work perfectly again on one cycle.What I really think is wrong is possibly the capacitor.How do you check that ?