1968 Barracuda washer pump positive terminal question

Umm, the wire you have shown is for the low brake pressure warning switch on the distribution valve for your brakes on the LH framerail. This illuminates the "BRAKE" indicator in the dash that's used for the parking brake. A low pressure in the brake system actuates the same light as a warning.

Electric washer pump is a brown wire female spade. It was an add in on the assembly line. OEM wiring harnesses do not have this wire unless serviced in at vehicle assembly. My harness made by M&H does have this wire serviced in, but it's not typical of OEM in that regard.

If your harness doesnt have it, typically it consisted of 2 brown wires one was male and female and plugged in at the pump and firewall. Another brown met at the bulkhead and plugged in at the wiper switch. Factory harness 2 speed wiper cars, did not have these 2 wires. That particular cavity in the bulkhead was unused, ditto for that cavity on the wiper switch plug in the dash.

The 3 speed and V speed got pump electric power from the switch itself being powered. When knob is depressed it just closes the contact as it rotates to the low setting basically juicing the windshield as it turns on the wipers to the low setting.

If your switch is a 2 speed type low, high, and off if does not have washer capability. Only 3 speed and variable speed switches do.

I been down that road before. If it's a 3 speed or V speed switch, you need the corresponding wiper motor to go with it.