Fan speed issue

[DennisT]

One of our Fantastic vent fans seems to be running slower and changes speed in its own from time to time while running.

Has anyone seen this issue before?

They are not the temperature controlled ones but variable speed from the wall controller with rain sensors.

Will be calling Newmar but wanted to see if others have had this issue.

 

[DennisT]

Update on the fan speed issue…..

Spoke with Newmar and Dometic and received troubleshooting requests.

While monitoring the fan speed check the voltage and current going to the fan motor. Luckily I have a meter that has a clamp on ammeter.

While on the roof taking measurements I noticed a plunger switch that the ground wire from the fan connects to.

Turns out this plunger switch is sticking.

Touching the plunger permitted it to raise the rest of the way and the fan speed went to normal.

Updated Newmar and Dometic with the latest info and they are sending a replacement switch. Much easier than the whole unit or motor, etc.