On Wed, 18 Jun 2014 10:29:59 -0700 (PDT), wrote:

I converted an old blower motor as well but the motor gets very hot after about an hour or so of running. The cord doesn't get hot. I am 99% sure that its wired correctly. There are five wires plus a ground (C,1,2,3,4). See photo below. I bought a two speed switch and wired speeds 1 and 4.

https://lh5.googleusercontent.com/-TiN2LqiPGhs/U6HKV0mPGLI/AAAAAAAAB8I/HyYHHiYZZ6Y/w534-h712-no/1385931304185.jpg

The fan works great but just gets hot and has actually locked up once. Luckily I was right there and shut it off. At first I thought it might be a 220V motor but I can't find any indication of that anywhere (see photo below).

https://lh4.googleusercontent.com/-xsAKs5QHOf4/U6HKV9Y0QQI/AAAAAAAAB8I/C6hTXLAsBJY/w949-h712-no/IMG_20131201_154842.JPG

Then I thought it might need a capacitor but it was never wired for one. The fan spins freely so I don't think the bearings are going out but anything is possible. The fan was sitting in another garage for years and I don't think it was ever used for very long. I just don't know why its getting hot and has locked up once. Could it be that I need to restrict air flow like others have suggested? Is there something on the motor plate (photo) that I missed? Any help would be greatly appreciated.
The motor is designed to be cooled by air moving through the air
handler cabinet. You now have it out in open air?? I'm assuming a belt
driven fan - not dierect drive? install a small fan blowing air over
the motor and it will LIKELY run constantly without overheating.