Need to turn on frig fan when TM is closed?

[benjburton]

For the year I've owned my TrailManor, I've always plugged my camper in, in my garage, the night before the trip to get the refrigerator cooled down. I haven't had any noticeable issues with doing this. However, after reading a number of these posts, I've learned that it's probably not a good idea.

So I wired an external switch this weekend, which was very easy given the location of the wires to tie into. Opening up the access panel behind the refrigerator, it was very easy to see the 2 wires running under the very bottom of the flexible vent pipe to the fan, where they were very conveniently connected with wire nuts to the power coming from the interior switch. This allowed me to easily wire a switch in series. There was a convenient conduit nearby to run the wire from the interior compartment to the exterior bottom of the camper. I zip tied the toggle switch to the wires at the bottom of this conduit, allowing for easy access while the camper is closed.

For the external switch to work, the interior switch must be turned on as mentioned above. This switch does have a light, so unfortunately there is some electrical draw here. My plan is to eventually wire an on/off switch at the battery (not just for this reason), so this won't be an issue in the future.

[bonusvalue]

Here is the part to buy:

http://www.ebay.com/itm/DC-12V-F-Fah.../141777090187]

http://www.ebay.com/itm/DC-12V-F-Fah...-/141777090187

I am not much of a electrician so here is my question : Where do you get the 12V to power the controller (red and blue wires)? Red is hot and blue is ground? Are terminals 1 & 2 wired inline with one side of the fan switch?

[ThePair]

Originally Posted by Bill

I'm pretty enthusiastic about this 3-way switch solution.

If you put two switches in series, the inside switch must be ON before the outside switch will do anything. If you forget to turn on the inside switch, you are out of luck.

And if you put two switches in parallel, the inside switch must be OFF if the outside switch is to have any function. Again, if you forget to pre-set the inside switch ...

But just like the three-way light switches in your house, a three-way hookup of two fan switches, one inside and one outside, lets you turn the fan on or off, from inside or outside, without regard to the position of the other switch.

Thanks, Tentcamper.

Bill

I have one switch in a waterproof box that is both on/off for the fridge DC circuit, and on/off for the fan. The difference is that I have the fan set up in parallel so that both this outside switch and the inside fan switch can turn the fan on, and the inside switch ON will keep the fan running regardless of the outside switch.

Why would I do this? So that if we stop on the road, I can turn off the DC circuit to maintain the battery, but still have the fan running -- there will still be residual heat in the compartment for quite some time and I wanted the fan to keep operating. But, if I forget to turn on the inside fan switch prior to closing down, flipping the outside switch will guarantee the fan is running any time the DC circuit is running.

It also means I can have all the power off to the TM, and then turn the fan/fridge on from the outside to cool down, but there are many ways to skin that particular cat as well (battery cut-off switch is another, which I also have installed).