I have a car ignition switch that has 4 settings and is +12v 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 can't seem to figure out how to do so.