Intermittent no blower control on all low speeds?

1993 Acura Legend mileage: 145,000 initial symptom was intermittent blower control on all low speeds and always works on max. Max speed failed and over the phone, the Acura dealer stated a bypass transistor was the problem. Acura dealer installed bypass transistor with no positive results. He then stated the blower motor was at fault. Dealer replaced motor, again with no positive results. He kept my car for another couple of hours and stated it was the blower motor/temp control unit in the dash and it cost about $1600. I personally replaced the control unit from a salvaged auto with the same results. You can hear the relays click but no blower motor working. I removed the blower motor from the car and connected it directly to the battery and it appeared to work. I reversed the leads and connected them again like original and the motor blew extremely hard. I disconnected and connected the leads to the battery several times but could not duplicate the extremely strong air movement, but it would always blow when connected. What is my faulty component/components? Any help/advice would be appreciated. The car is in great shape except for that. I would hate to hardwire the blower motor, but it is starting to get hot in Texas.