I have this same problem, blower only runs on high. It started after someone stole my stereo and so kindly cut all the wires to the AC control head. So I had to get the plug ends from a salvage yard and re-wire the whole mess, not to mention a new control head. Now the blower only works on high speed. Yes, it is wired correctly. However I did get it wrong the first time because there are several wires that are color coded the same. So I may have caused something to "burn" out. Anyway if you could send the file to me I will greatly appreciate it. marioanest@gmail.com