TR4/4A TR4A Wiper Motor

[6TTR3A]

All references say the 4A wiper motor is a 2 speed. A look at
a correct wiring diagram shows a wiper switch with two
settings, F & S. The motor I'm looking at has three wires
coming out of a common grommet hole plus a threaded hole for a ground wire.
Does anyone know if the motor really is a two speed or is the switch just a fancy rheostat that regulates the power to the motor???
HELP!!!!
FRank

 

[TR4A_IRS]

My wipers have three speeds. Off, Slow, and Fast.

 

[TR3driver]

This might help

 

[LBCs_since_1988]

TR4A wiper motors are two speed. As stated the operating switch has off (pushed all the way in), low, and high clicks.