Fuel pump relay wiring?

I have an intermittent problem on my truck listed above. At times, the fuel pump does not activate when the key is switched on. There’s no rhyme or reason when this happens. Over the past few months, I have tried a new fuel pump relay and fuel pump inertia switch. The issue still occurs sometimes. If I remove the fuel pump relay and place a jumper wire across the 2 slots in the fuse box to activate the fuel pump, it turns on and the truck cranks/runs fine. That tells me that the wiring from there to the fuel pump is good.

I have removed the fuse box from its bracket and checked the underside of the box for any broken/brittle/corroded wires on the relay slots. The wiring looks fine there. I checked the under-hood ground connections on the inner fender well and they looked good as well. Any ideas?

Does anyone have a wiring diagram of this circuit? The relay has 2 pins to power the fuel pump and 3 pins on the other half of the relay. I’m trying to see the what the 3 pins are for.