Closing the Fantastic Fan

israndy

2007 LTV Serenity
I don't often use the Fantastic Fan in the RV for cooking odors, I mostly use it to keep the van cool when the sun is shining. The fan has the rain sensor that closes the top when it would get wet inside and the thermostat that turns the fan on when it gets too hot. What a great solution, except in the fall, winter, and spring when the temps at night get too low to be comfortable and all the hot air has risen out of the van. Glad as I would have been for the fan running all day if I came back to it while the sun was up I am often disappointed how cold it is and the fan is still open at night.

For a LONG time now I have been planning on running a wire to the thermostat. I had to replace the thermostat with one that allows turning the heat off and on as I discovered it heating the van at night when I was not there even though it was turned all the way down. The only way to turn off the furnace was to take interior body panels off. A new thermostat that was both heating and cooling also offered a middle switch that was off.

Problem was that the interior vinyl was difficult to get behind to hide the wires running to the fan and so I have yet to accomplish this simple task. Today I finally gave up when I came across the Temp-Stat temporary construction thermostat.
Temp-Stat.png
OK, yes, it is a SECOND thermostat purchase for the RV, but at $18 on eBay, I can't complain too much. I got the CL-70, the cooling, switched at 70 degrees Fahrenheit thermostat. When the temps go over 70 it turns on the circuit and below turns off. Thus when it arrives I will simply wire it into the switch that opens the fan and it will ignore the switch when the temps are below 70.

This may mean that the wife is upset when she cannot turn the fan on, but it will also mean that I never need to flip the switch again for normal use it will open the roof when I want it to and will kick on the fan when I set it to. When the night comes it will close the roof instead of loosing all the warmth of the day out the top.

-Randy

Cross-posted from Yahoo Gulf Stream Vista Cruiser MB group even though it's going in the new Serenity
http://autos.groups.yahoo.com/group/GS_Vista_Cruiser/message/161
 

israndy

2007 LTV Serenity
Updating my notes on what work I have done on the Serenity and I came across this entry. Seems I never finished detailing the adventure. I don't know why EVERYONE hasn't followed in my footsteps cause it's so easy.

See that switch that you use to turn the fan ON? Flip it and the lid starts to open? OK, find that same switch in an SPDT design with center OFF, it will have 3 legs instead of two and click to 3 positions. I would say Go to Radio Shack, but since I posted this originally they went tits up. I got mine at an electronics store anyway, Al Lasher's in Berkeley CA.

OK, take down the fan, that's 4 screws. You can do it. It will hang by the wires connecting it to power and such. Squeeze the old switch out and unplug the two switched wires. Now hook the new switch in BUT you are going to run the construction thermostat to the 3rd leg, so get a crimp tool and put a blade connector on one leg. For the wire going to the center of the switch (doesn't matter which of the original wires it is) you need to piggyback on that center wire. There are two way blade splitters that would work:

56032bl__25019.jpg

or there are wire taps that cut into the insulation on the wire and allow another wire to be connected:

page2c.jpg

Hook the other end of the thermostat to the wire going to the center of the switch. Just tuck that all under the plastic housing and put the 4 screws back in and you are DONE!

OK, so in the center position the fan is OFF and the lid will close. Switched one way the fan is just ON, like always, the other way the fan is ON when it's over 70° in the fan area. This allows me to turn the fan OFF in winter and ON the rest of the year. When it get's warm in the RV the fan opens, when it gets warmer still the fan spins up based on the original thermostat. When it rains the lid closes unless your rain sensor is getting old. That's a pain, the folks at Fantastic Fans think this doesn't happen and will rebuff your attempts to get replacement parts. I found mine on eBay. When the sun goes down the lid closes and another day is done.

The fan does use significant power, so don't walk away from an RV that doesn't have solar panels on it, or that is plugged into shore power. It won't kill your battery overnight, but it will soon enough. When the fan first opens or closes it will stutter, it opens, all the heat gets out, the internal temp drops, the lid closes. But usually only a few times each way. The down side of automatic.

Total cost was $4 for the 3 position switch and $18 for the thermostat. I already had the crimp tool and connectors.

-Randy
 

israndy

2007 LTV Serenity
Also the Serenity didn't have a reverse switch, the the fan ONLY blew out. My old Gulf Stream did, so I swapped the switches between the two when I did the thermostat update. I think the FF people will sell or give (they have NEVER charged me for anything they sent me) you a reverse switch. Helps on hot days when you want to feel the fan blowing on you directly to cool off.

-Randy
 

Top Bottom