Pump(?) Continuing to Run After Shut-off

'87 B2000 2.0L
New owner (3 months). 4,000 miles (272,000 total). Just had the oil changed and all fluids are good.

Fueled up this morning, and when I started up, I thought I heard a whining/whirring coming from somewhere (windows open). Chalked it up to another vehicle, because my sh*t is perfect, right?
Get to work 30 miles later, shut off the engine, and there's this pretty loud noise coming from under the hood, like a pump, and kinda sounded like some fluid was being pushed around (noise-in-pipes sort of noise). The engine also refused to restart, or even turn over. Just like a dead starter or battery, except I have electrical power.
Lifted the hood - sound seemed to be coming from the left side, near or below the carb/intake. No freaking clue what it is, don't know the engine very well.
Had to get in to work, though, so I played a hunch and disconnected the battery (thank God for Gerber Multi-pliers!). Noise stopped.
Damnedest thing I've had happen on a vehicle...

Thoughts?


-502-

Automatic or 5-speed? Automatics have electric fuel pump (did they even have automatic ones in 1986?).

Starter?

Yep - starter.
Couldn't get a good look, but got my hand down in there. Wires are fine, completely separated like they should be. Felt one small wire connected too, like it should be, but there was another, blue wire with

No, ignition switch issues are not difficult to troubleshoot and fix on these. Especially if a circuit had power when it shouldn't !!!

Eehhhh, maybe, maybe not. I can figure my way around mechanical stuff, but electrical system might as well be Chinese algebra

Five0two... I'm guessing from the bluegrass?

If the starter is still spinning even after turning the key off, it may be possible the key cylinder is bad, i.e. giving power when it shouldn't. I know the key cylinders / ignition switches typically go bad in the these truck after a couple thousand miles.

Perhaps someone tinkered with it? The plastic cover on the steering column is easily removed. There are five bolts on the underside. I'd take a peak and see if a previous owner monkeyed with anything.