Yes but that motor runs 2 squirrel cage fans, One fan is the combustion fan, which provides combustion air to the burner, which then pushes the hot burned gases through the inside of the heat exchanger.
The second fan is the fan that moves from the coach over the outside of the heat exchanger and removes from it to the air, then pushes that air into the coach.
Now if you run that fan without the burner burning then cold outside air is being moved through the inside of the heat exchanger and is cooling the air inside the coach. Which could cause condensation in the heat exchanger and cause it to rust out.
I hadn't thought of that. Guess running the furnace blower is now out of the running!
The adavntage is warm air from the RV would be blown down into the tank area, The secondary advantage is air circulation in the living quarters would tend to level out the temps from front to back from near the space heaters to not so near, in short, There are advantages.
I posted what he needs in another forum
NOTE: He and I have the same furnace make/model. I just spent a bunch of time working on mine figuring out it needed a new control board, OEM 250, Dinosaur about 100 with shipping included (108) I like the look and feel of the Dino board way better than the OEM, plus it has protection against what I think killed the original.
Back to topic. He needs to remove the BLOWER wire (RED) from the control board, This is a tab type connector, standard size, easily removed.
This he extends to a switch, SPDT. Center terminal
A wire from the original tab runs to one end of the same switch.
And a wire from the BLUE wire on the circuit board to the other end of the switch.
Optionally a LED indicator from the center terminal to ground
Optionall a DPDT switch, so the LED only lights when he's on MANUAL blower.
NOTE to OP.. I happen to have a short pigtail with the connectors you need at the furnace end (it came with my dino board) if you want it. Alas, would take me a while to get it to you, I'm not selling it.. (That is no charge save SASE)
Nothin adds excitment like something that is none of your business
Kenwood TS-2000 housed in a 2005 Damon Intruder 377