Originally Posted by nothermark
It can be replaced if you know how to solder parts on a circuit board.
FWIW I'd ignore it or look for a multi stage converter with about the same amp rating.
Agree in both points. If you feel comfortable diagnosing a component on The controller board you could probably find the relay. Not sure you'd be able to find a replacement part but that's another story.
One more step to diagnose the problem Either take your battery into our automotive shop to get it tested or put it on the charger disconnected from the RV until the charger shows it's good.
Then reconnect to the RV. If the fan still runs then likely the controller board. (~$100). The controller board is fairly straightforward to replace.
If you plan to keep the trailer I would strongly encourage you to get a better cconverter/charger as mentioned above.
But note a new converter charger will be a nasty rewire mess. Not impossible just time consuming.
Also it occurred me that since the fan never used to run before perhaps now the temp sensor or heat sinks are covered with dust so you might consider using an air hose to blow out the dust from the converter.
This all is under the assumption that the fan noise bothers you. It bothers me too but not enough to make the change.
I had wfco in my keystone and anything more than 3 lites on and the fan would run. My progressive dynamics converter in the Starcraft rarely turns on the fan. My guess is one has larger heat sinks or convection cooling design that precludes the need for a fan.