lift pump running

[Jurek]

Shut off the truck yesterday./key out off ignition switch/. Go to the truck this morning, hear the lift pump running. Wiggle the gray connector on the oil pressure switch, it stops. I took off the connector . They are 3 wires, one of them are hot, even if the ignition switch is off/key out/. Is this the way it should be, or I have bad relay, oil pressure switch, or some kind of electrical short. I have removed fuel pump relay, wire still hot. Truck is 97 2500 GMC 200k miles. Thanks for suggestion. Jurek

[scottm]

It sounds like maybe the ops or relay contact has welded closed. If you put the ops connector back on, does it start running again?

[john8662]

Bad Oil Pressure Switch, there is power at the connector with the ignition switch off.

Recommend an AC Delco D1808A replacement.

[Jurek]

Thank You very much. This is what I wondered, if is the power on the connector with ignition switch off. Jurek