I have a car ignition switch that has 4 settings and is +12 V DC:
- 0 = off (no voltage)
- 1 = accessory (only some items have power) (no voltage will go to pump)
- 2 = on (all items have power)
- 3 = start (momentary switch for start power)
I have a pump I want to wire up in the following way:
- When the switch is on 3 (momentary), the pump gets power and turns on.
- The same switch then moves to setting 2, where the pump remains on.
- If the switch is turned to positions 0 or 1, the pump turns off and will remain off until the switch is returned to position 3
- The pump will NOT turn on in position 2 alone, but will remain on in position 2 AFTER position 3 has activated the pump.
I believe this can be achieved with two SPST relays, but I can't seem to figure out how to do so.
Is this a good way of doing it?