Air Conditioner vibration

[joebedford]

My toy hauler was stored over the summer. When I hooked it up for snowbirding in December, the a/c's both cooled fine but both vibrated as soon as the fans started. The main a/c stopped doing it after a while but the one in the bedroom seems worse (or maybe that's my imagination). I can feel the vibration at the other end of the RV in the garage.

Is it possible that some insects build a nest in there?

I guess it's time to climb onto the roof and inspect the fan.

[joebedford · Accepted solution]

I finally worked up the energy to climb onto the roof and remove the a/c shroud. Sure enough, there was a hard 3" mud nest by the hot side squirrel cage but it had fallen off the cage and was lying on the floor of the a/c. I had DW turn the unit on while I watched it and the motor was still shaking back and forth about 1/4". I concluded that there must be more stuff on the cool side fan. Sure enough I could see 3 50 cent sized blobs on the inside of the inside squirrel cage. I was able to get most of the mud out by poking a screwdriver through the fan louvres(?). There was also a 3" blob on the wood frame for the a/c. I removed all the debris and the fan is much smoother now - still a bit of vibration but for all I know that's how much it has shaked ever since the rig was new. Storage covers this summer. Anyway, problem solved.

[QCMan]

Seems like mud daubers have set up house in the cavities of the fan. You will need to take the outside cover off of the air conditioner and look at the fan. The issue will be obvious. Had that happen on a hot to cool to hot trip. Seems that the buggers made a nest after I shut it off and before I needed it again. I thought the unit was going to fly off the roof.