It's a solenoid, polarity doesn't particularly matter here. Typically one is grounded and the other is 12v via a high pressure switch and a relay.

1972 Barracuda - 5.7L Hemi, T56 Magnum 6spd - https://www.facebook.com/GoodysGotaHemi
2020 RAM 1500
[img]https://i.imgur.com/v9yezP9.jpg[/img]