AC fan will not start

[StephenandRobbi]

I have a Duo Therm AC model 57912. When the unit is turned on the fan will not start. It will run if you give it a turn by hand. I replaced the start capacitor and it did not help. I don't see any reason to suspect the run capacitor so I'm leaning towards replacing the motor. Any thoughts?

Thanks,
Steve

[StephenandRobbi]

Ok, everyone who voted for the run capacitor, you are correct. I replaced it today and the AC seems to run fine. Thanks again for all the help.

Steve

[Chris_Bryant]

Just replace the run capacitor and it will be fine. FWIW, I have only found a motor with electrical problems once , and that was due to being hooked up incorrectly. Every other motor I have ever replaced has been due to bad bearings (and I have replaced a bunch).

[StephenandRobbi]

Yes, I believe there is only one fan.

[Ex-Tech]

prolandsurveyor wrote:
Are u talking about the blower motor? The motor that blows air inside the camper? Or the condenser fan motor that blows air on the top of your camper?

On a RV air conditioner, the same dual shaft motor operates both the evaporator and condenser fan.

[prolandsurveyor]

Are u talking about the blower motor? The motor that blows air inside the camper? Or the condenser fan motor that blows air on the top of your camper?

[StephenandRobbi]

Thanks for the info.
There are only 2 capacitors in the system. A run and a start. Since it would run once started I assumed the run capacitor was good. It will run in either direction though. So I guess the best rout is to replace the run capacitor and then the motor?

Steve

[PaulJ2]

Chris Bryant wrote:
The start capacitor has nothing to do with the fan. If it spins freely, replace the fan capacitor. (You can double check and try spinning it backwards- if it runs backwards, the fan capacitor is definitely bad)

X2 on this.

[MEXICOWANDERER]

Every last one I have ever torn down with those symptoms had a burned coil or two in the stator. Time to grit your teeth. Low voltage is a usual suspect.

[Chris_Bryant]

The start capacitor has nothing to do with the fan. If it spins freely, replace the fan capacitor. (You can double check and try spinning it backwards- if it runs backwards, the fan capacitor is definitely bad)

[pianotuna]

Hi,

If there is a setting for running the fan constantly use it.

Some folks have tried to oil the (probably sealed) bearings.