How to add a Thermostat to an RV Vent Fan

RV Van Vent Thermostat Wiring Demo in the Workshop

So I was looking through the footage I shot in the camper and I don’t think I did the best job at explaining how I have this thermostat wired in.

I’m in my workshop and I’ve got a 12 volt battery, a thermostat, and a small fan and a heat gun to do this demonstration.

I have from the battery wire from the positive and it’s going into the C connection on the thermostat. And out of the thermostat it’s connection number 2.

That is the positive — I have it running through this little 12 volt to 5 volt converter for this fan, as this is a USB fan but, it’s good enough for the demonstration.

Then returning from the fan the negative goes to the negative terminal of the battery.

It’s about 67 degrees Fahrenheit or 19 degrees Celsius in this room. I have the thermostat set to 30 degrees Celsius or 86 degrees Fahrenheit and with the heat gun I’ll apply some heat to the probe.

Okay, so, the fan just kicked on.

In the camper the fan would be cooling the entire space of the RV not just cooling down the probe as it is in this demonstration. And it’s off so it’s cooled the probe down below 86 degrees Fahrenheit. So I think that’s a little bit better explanation of how I have this wired together.

Remove the RV Vent Fan Housing

There’s four screws that hold the vent trim ring in place.

With that removed, I can see the positive and negative wires that supply power to the vent fan.

Then there’s a screw holding the lid crank handle on its shaft. And the speed selector dial can then be pulled off. Then followed by a four amp fuse.