Got Motorhome to the house to ready for an upcoming trip, fired up genny and put on front air unit...roof began to rumble like someone was up there dancing. What now? Determining issue was fan not compressor I set out to investigate. Had my brother climb up on roof (I don't do roofs
), removing the cover of the unit (on roof) revealed that some Mud Daubers had built a mud nest on the end of one of the condenser fan blades, the weight of that combined with a couple of mounting bolts for the fan motor that had come lose, we suspected we had found the problem. Glad to say, ran smooth as silk again.
He did note however that the shaft that the fan is mounted to has rusted or corroded to the point where it is very thin near the fan blade mounting point. It seems odd that it would only rust at that point, wondering if there is some issue there with dis-similar metals. Rear unit had no such issue, same model, age, size, etc...