Older 7900 series blower problem
Posted: Tue Sep 21, 2010 5:43 pm
This is a 86 model trailer with a Coleman 7900 series HVAC
I replaced the blower motor and capacitor a couple of months ago with new parts when the original motor gradually quit working (slowed down in rotation speed until it was at a crawl but like I said it did it slowly so it was not noticeable).
The new setup has worked fine up until the last day.
I recently smelled something each time the A/C would start up, and hearing a humming sound comming from inside the cover, took the front cover off of the blower area to discover the motor was very hot to the touch and just trying to turn, not turning. Best guess one revolution in a minute..
When the motor starts, if it rotates, it rotates very slowly, and the house lights dim and brighten several times while the motor tries to come up to speed. I think that over heats the motor and that is what I am smelling. The motor was barely moving the fan.
The last few times I have helped it get rotating to get started, once the motor gets up to speed it seems to runs ok until the A/C shuts off and then we start over again when it restarts.
With the power off to the unit, I can reach in and the fan is loose and spins fine by hand.
I have set the switch for the fan to run all of the time, since the problem seems to be at startup until I get this figured out.
Could the new motor or capacitor be going bad?
I have checked the wires, they are all hooked up securely and they are not hot even when the motor is very hot to the touch and will not start up properly without a initial spin to get it going.
I replaced the blower motor and capacitor a couple of months ago with new parts when the original motor gradually quit working (slowed down in rotation speed until it was at a crawl but like I said it did it slowly so it was not noticeable).
The new setup has worked fine up until the last day.
I recently smelled something each time the A/C would start up, and hearing a humming sound comming from inside the cover, took the front cover off of the blower area to discover the motor was very hot to the touch and just trying to turn, not turning. Best guess one revolution in a minute..
When the motor starts, if it rotates, it rotates very slowly, and the house lights dim and brighten several times while the motor tries to come up to speed. I think that over heats the motor and that is what I am smelling. The motor was barely moving the fan.
The last few times I have helped it get rotating to get started, once the motor gets up to speed it seems to runs ok until the A/C shuts off and then we start over again when it restarts.
With the power off to the unit, I can reach in and the fan is loose and spins fine by hand.
I have set the switch for the fan to run all of the time, since the problem seems to be at startup until I get this figured out.
Could the new motor or capacitor be going bad?
I have checked the wires, they are all hooked up securely and they are not hot even when the motor is very hot to the touch and will not start up properly without a initial spin to get it going.