OK
Your main concern on that test is that the Control Panel is giving you the variable V at that yl wire b/c that is the blower speed trigger signal for the blower regulator..if you have no trigger sig to the regulator, you have no blower.
And no trigger is upsteam from that connector, not down-stream [ meaning down at the blower/regulator.]
You must meet those two voltage checks before going down into the blower/reg end.
If you have no V sig from CP, then it could be as simple as a bad feed fuse for CP. [ fuse #7 on your chassis]
If both test are YES at that 3 wire plug, then you have a problem down at the blower/reguator compartment.
In that case , you would jumper a wire from the BLU wire to ground..if that gets you High Blower , you have a bad regulator... see many guys change the reg only to find out later that the reg was fine and was simply not getting trigger V from CP... a costly mis-diagnosis.......

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A Dalton