We got ourselves in trouble with an old furnace. We need to replace the motor but took evertthing apart without marking anything.

What we have. Coming from the Furnace - Red, Blue White
On the Relay 12900 RBM 2 blue light wires, One Brown and One Red to a Small switch and One Brown and Red Available

THe Motor has 2 brown going to a solenoid.
Available are White, Black, BLue REd. I believe WHite is common, And red blue and black are speeds.

Help

Its time to call a professional. If you mix wires or if the original wires was ever replaced it will do more damage than good trying to guess how to wire.