Exemplary Furnace Fan Speed Wire Colors

The black wire is usually the highest blower so that s why you should start with that one.

Furnace fan speed wire colors. On 120 volt motors. Usually go to capacitor. Find and remove the cover.

Last you ll want to make sure this motor can operate using 140 volts which will be indicated on the motor. Your furnace should have a sticker that tells you the normal range for each of the wire colors. It comes from the factory with the black plugged into cool and the orange plugged into heat.

You should be aware that this may have changed especially if the person who wired the thermostat didn t use conventional color coding. White is the common or ground then progressively from lower to higher speeds the colors normally go red blue yellow and then black. Video demonstrating the standard wiring for the primary blower motor found in most furnaces and air handlers in residential hvac.

Blue and red are hooked to m1 and m2 which are just place holders. There are only a few steps required for most units and having the control will allow you to get your unit to give you the service you need. 2 brown for the capacitor a white common wire black for high orange for medium high blue for medium low and red for low.

Example white to black check resistance. White wire for w terminal. These speeds are represented by color coded wires.

Hope this helps a few folks. The white wire connects to terminal w in industry standard thermostats. This wire should go directly to the heating source whether it be a gas or oil furnace electric furnace or boiler or auxiliary heating for a heat pump.