2 SP WIPER SWITCH WIRING
We were discussing this off line and here's what we found.
In the '72 FSM and there's some explanation and guidance for a two speed system troubleshooting starting around page 8-107.
From the diagrams in the back of thee chapter
Terminal
B is "Battery" and is fed from a splice in the Accessory circuit (
wire Q2)
Looking at figure 5 in the chapter
Terminal
A gets power directly from the B when the switch is in Low. Wire
V3 goes to resistor and then
V3A to the motor.
Terminal
F1 gets power directly from the B when the switch is in High. Wire
V4 goes to the motor.
Terminals
P and
F2 provide power when the switch is turned off, but only until the wiper reaches the down position when contact is broken.