Hi jeffo, welcome to the SOC.
I don't have a lot of experience working on the furnace but Kitty got you off to a good start, you need to make sure there is a good 12 volts first. Next make sure the blower motor CAN turn, give it a spin by hand to make sure (
you probably already did). The blower motor gets its 12 volts from a control board when the thermostat calls for heat. One side of the motor should be ground (usually black wire), hot side (usually red wire) should have 12 volts from controll board. When the blower is blowing it causes a "sail switch" to close to allow gas to flow and then the igniter to light the gas.
I came accross this which may (or may not) be yours but it should lead you somewhat through the wiring.
http://www.atwoodmobile.com/manuals/...0SP%201.08.pdf
Gene