74 Heater problem solved

Been rebuilding the heater in my 74 and reading all the posts. Took everything out and cleaned it all out. Made sure all then flappers worked well and put in a new heater core. The motor that was in the Jeep when I got it had two wires, a black and an orange. Took a while to figure out one was ground and one was 12v and that with black to power and orange to ground it turned in the proper ccw direction. I had a hard time figuring out how to get two speeds out of it and read some posts about adding a registor to get the slow speed. But the 74 didn't come with a resistor so I didn't want to go that route. And besides the speed it was going wasn't all that fast anyway. I ordered a motor from Quadratrac that was advertised as a two speed motor but what came was the same motor I had. I guess two speeds was one speed cw and one speed ccw. Sent it back and started researching motors. I found a motor by Kysor (part #1099040)that matched all the dimensions of my motor with the same shaft size. Can be wired to run cw or ccw. Available from Unity Bus Parts. When it came it was indeed a two speed motor and blew like all get out but it wasn't reversible and ran in the wrong direction. Turns out that motor cross to a motor from Bluebird (part#0159723). Everything the same except the rotation. Sent it back and ordered their reversible motor part #GR157. It came and it is reversible and two speed and mounts right up. Blow great. My old squirrel cage though wasn't balanced and vibrated horribly. So I ordered a new squirrel cage from Unity. Part #1-6000. CCW rotation to go with the CCW motor. Part came and everything ran smooth as silk, but the cage was for the wrong rotation. Called Unity. Turns out motor rotation is determined looking at the shaft end. Cage rotation is determined looking good at the end the shaft goes into. So for a CCW motor you need a CW squirrel cage. Go figure. So I finally got the right cage and put it all together. Puts out great heat on slow speed and will drive you out on high. But we are in the middle of spring. I think it will work great in winter too. Even gets good air flow at the defroster. So to sum it up, Unity Bus Parts #GR157 for the motor and 1-6048 for the cage. Bolts right up, no mods. Same motor dimensions. Connects to the two speed heater switch. Works great.

 

Great work. That should help a few folks.