<<The red is system voltage 12 or so, the yellow is the control voltage signal for the blower regulator. It varies depending on the speed setting on the ACC panel, but it should be between 2.5 and 7.5 volts or so (don't remember the exact numbers) The black is ground. Get a voltmeter, unplug the connector and check those voltages (with the key on and either high or low speed selected, or, better yet, select defrost.) If they are OK, then it's the motor,>>
If they are OK , it is a sign that the Regulator is not tripping
on [ the yellow is the trigger] or the motor .
The 12 volts [ black and red] has to get to ground through the regulator, so power at the plug does not diagnose motor/regulator. Could be either.