How to set Nest Thermostat to control blower without heat

blowerfanslennoxnest

I have a Lennox G14Q3 propane furnace (forced air). I used the Nest/furnace setup last winter without any problems with just the W and R terminals.
But, these summer days I would like to push air through the house with the blower (without heat) and remove it with my HRV system.

I’ve tried hooking up the terminal G to the G terminal on the Nest (for the fan). But the Nest can’t seem to turn it on.

Note: When I test the heat with the Nest, my furnace goes through it’s standard cycle of heating up then turning on the blower.

Also, I can’t seem to get the blower going down at the furnace by shorting R and G, shouldn’t that work?

Thanks,
Josh

Edit, added model and diagram pictures:
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EDIT 2:
I realized that ACC isn't actually connected to anything. It gets 120VAC when I switch the relay, but there is still no path to the blower to be energized.
Could I just take one of the speed wires from the blower motor and connect it to ACC so that it acts as an indoor blower?
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Best Answer

Alright, I figured out why it wasn't working. Had nothing to do with ACC not having a lead. I was looking at my setup closely and noticed that only 2 wires were coming up from the motor, but it needs 3. I noticed that there was a wire coming from pin 3, but it was crimped and didn't run to the motor. So I looked at the speed table and decided I wanted to run the Brown wire up. Connected it to pin 3. Now when I short R and G, the fan turns on :) enter image description here

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