Why, yes, that's a plausible mode of failure. I must compliment you, everything you say is logical.
I'm waiting right now for a ride to the truck. It's driving me crazy just waiting.
According to your pic, the relay containing box is in the engine compartment on passenger (right) side. I'll find it, wherever. I know the other relay box is under the dash on lift side of steering column, but that doesn't contain the fuel pump relay.

~~ Nehmo