Air conditioner motor seized from rust

[markopolo]

Ok, this is not on a B but most of these parts are similar.

My Dometic roof air conditioner motor was seized from rust. The fan wouldn't start. I took the cover off and tried to move the fan and it was seized up. I had to use my vice grip pliers to get a grip on the shaft to move it. Then I turned the fan on and it still wouldn't run so I went back up on the roof and with the fan switch still on and moved the blades until it started spinning on its own. The RV sat unused for a year before I got it.

I left it running for a hour or so. It will restart now without my assistance. I'll try it again tomorrow.

Has anyone had this happen? Do I need a new motor or should I chance it? Any advice will be appreciated.

[renrut]

I've worked with my father in airconditioning a bit when I was young and this is common. Depending how old the motor is, there could be oil felt around the bushings where the shaft spins in. If you can get at them, soak them with oil. If the shaft is baddly rusted, you might want to take very fine emery cloth and smooth the shaft out. Just oiling it might be enough.

The one thing to watch for are brushes. If the motor has brushes, they tend to shoot out when you take a motor appart. More than likely, that motor won't have brushes but if it does, there usually small pin holes you place a pin in to hold the brushes back when you re-assemble the motor. Once together, you remove the pins.

[g1g]

I have had that happen to several motors. None of them on the RV though but same problem. I had various results. One was OK yet two others froze up everytime that sat for lets say a week of non use. Finally replaced them. I also have one on a heater that once broke free it just runs slow. I don't use that heater but if I do I will have to replace it.

[markopolo]

So far so good. I ran the heat pump for two hours tonight. The fan started by itself. When I have time I'll see if I can take the motor out and clean it, oil it etc.