Need opinions. 89 k30 in tank pump issues.

[Kaysen]

Recently got an 89 k30. It's originally a tbi 350 truck that has been converted to carb with an aftermarket pressure regulator/gauge feeding the carb. The truck has sat for 3 years without running.
I'm not getting fuel out of the pump. Is there a way to test the pump in the tank and bypass all the computer and old wiring? I unplugged the pumps two wire electrical plug and connected a good battery to the gray wire and to ground but it still did nothing. I'm thinking it could be a bad ground on the pump but I'm not sure without pulling the bed. Any insight or advice? Thanks

The engine runs excellent if you keep the bowl full with a squirt bottle.