I removed the blue and red wires from the motor and supplied direct 12v and ground and the motor will run contantly.

What you shoud have done is left the wires on the blower and test from Red to ground for 12v...if YES, then take a jumper wire and go from the blu wire and ground the other end of jumper..if that starts the blower high speed , then the reg is not supplying the ground [ the red at motor is ALWAYS HOT with key ON, the switching is done by the reg on the ground side of the circuit...it is a Switched Ground circuit} Blu jumper is REG By-Pass.
If no 12v at red w/key ON , you have a bad fuse link up on top. If motor runs with blu wire jumper , then the reg is bad or it has no trigger voltage from the yellow wire.

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A Dalton