No power at fuel pump w/ jumped relay
 

My Express 3500 van shutoff on the highway and will crank but no start. Had several months of random no starts when it was raining out. Would come back a few hours later and van would start just fine. Had a random limp mode engage ~4 weeks ago but then went away upon next start. Had a check engine light for evap canister vent solenoid which was replaced and hasn't come back since. It's unclear if these are related or not.

Back to current issues: No fuel pressure on fuel rail. I jumped the relay and no pump noise. Checked grounds and all seem ok. I pulled the pump and there is no power on the fuel pump plug (the wide four-pin connector) at all. There is only power on one of the pins on the square connector.

Any ideas or suggestions on what to check next?

UPDATE
There appears to be 1-2V getting through when jumping the relay (but no continuity according to multimeter). I pierced the wire and confirmed the problem appears between the fuel pump relay pin connector and the gray power wire on its way out of the fuse box (shown on left).

(1) Is there anything between the port 87 and the gray wire leading to the fuel pump?
(2) Any ideas what repair may be needed inside the fuse box? How are the wires connected to the relay connector pins?
(3) Any ideas how to get the top half of the fuse box out without removing brake or AC lines?
https://cimg5.ibsrv.net/gimg/chevrol...de84837398.jpg

I’m having the same issue. Unhooked the batter for several hours and reconnected and it started working for a few minutes then stalled and quit working again. Already replaced fuel pump