regulator and relay

If you have a 70 or later with a clutch switch, you need a 4 terminal relay (two blades) same as an automatic. The older stick cars 69/ earlier had not clutch switch, and only had one "blade"

The clutch switch works exactly the same as the automatic neutral / park safety switch. it grounds that terminal (the coil of the relay) when in park / neutral or when the clutch is depressed.