Stop in for a cup of coffee

Petty Betty said
The brake lights work when you step on the brakes. If I turn the left indicator on then one left break light goes out. And vice versa with the right side indicator and brake light
Click to expand...
That's sounds correct.

edit.
found this while looking for something else.
1699010563861.png

Haz might be wired different in '75 but the stop and turn signals are the same as the 60s cars. Both power the larger filament in the bulb.

1699011433308.png
Orange represents the switch contacts signalling left.
The contacts connect the power from the flasher unit to the wires on the left side.