I deal with your type all the time
the 2 wire motor is 2 SPEEDS
the 3 wire motor is 2 SPEEDS
the switch's and its flow of power, ground or power side switched, are different
someone, maybe, used a 2 wire motor with a appropriate switch, and appropriate path of power.......made a 2 motor work in an original 3 wire setup.....if there was only one speed, you diagnosed it wrongly, a resistor may have been open
never the less, you came in and swapped motors, without that consideration, hence the ground was in the wrong spot
I offered a chance for you to be able to diagnose it, but you rather change a part that you had installed incorrectly.
so now come clean, you got another 3 wire motor, what else did you do to make it work?
cause I know, if you installed the second motor the same as the first, without a rewire, you would have the same outcome, motor no worky.
89 GT gr-40, KB2200(10psi), tweecer R/T,LC-1, 22gal cell, w/tailpipes.