I have a wood/electric furnace combination with a 3 speed motor. When I use the wood furnace, I would like to have the motor run continuosly on low speed. I need to change the wiring that goes from the manual switch to the motor. I know I only have to switch the wires from medium speed to low speed. How do I do this?
If not on the motor tag, try on back of blower door for schematic. Wire harness often in a box with a cover. You'll probably see some of the wires with the colors in the schematic 'going nowhere' with just a wire cap. They aren't being used. The 'real' one, under a wire cap but connected to the motor is the one currently controlling speed. With power off, switch wires.
But as biggles suggests, if you're going to change speeds often, consider a switch box control.