You are propably testing the downstream line when you unplug....I want you to test the SOURCE ...If you leave the connector plugged in, you can't make that mistake.

Anyway, the Red/Yl/Blk go from there to the regulator/motor.

So, if you have power up at X64 for both red and yl, using blk for ground , then you have to go down to the blower compartment.
There you check the RED again for pos 12 v w/key ON..if YES, then you jumper a wire from the blu to ground..If Yes , then fan Motor is verified as OK..now see if you have yl trigger at Regulator..if Yes , then Reg is bad , if NO , you have a break in yl from X64 3 wire test connector up at booster.

That is why we use X64 for testing before going to blower .. Many guys tear right into blower/reg , when all is needed is a simple X64 test I mentioned.
The blower circuit uses a "Switched Ground" circuit...where the 12v feed [RED} of the blower is ALWAYS HOT w/key ON...the switching is done by the regulator on the GROUND SIDE of the circuit [ negative side]...and that is why if you ground the reg blu wire , you are by-passing the regulator.
BUT ..many guys do that jumper test and assume they have a bad regulator...but the yl trigger signal wire has to be confirmed FRST before condemning the reg. Without that yl variable sig from the CC, the regulator simply does not work...it has to be triggered !
Don't make the costly mistake of replaceinG the reg until you have verified trigger V at yl...............see it all the time... $300 WORTH OF PARTS AND 3 HRS LABOR FOR A BAD FUSE.

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A Dalton