Relay

These trucks had some troubles with the fuse panel under the hood, when it's buzzing try putting pressure on the relays and fuses, also check if there's a large red wire laying on the driver's front inner fender(hood up looking straight down), would have a small junction block fastened to inner fender, near the brake booster, that connector breaks over time. Should be a single wire near the firewall, through that block, then split and go into under hood fuse box and alternator

Probably a bad relay. Hopefully it is not one of the built in ones.

Hello my name is Martin I have a 2000 Ford F350 V10 two wheel drive crew cab Super Duty fuel problem I put a fuel pump in 2 years ago that correct the problem now just about a week ago put a new fuel filter in 2 days ago now my truck starts in the morning but wont start after I turn it off acts like it wants to start but won't only in the morning? Is that relay fuel switch and fuse thank you very much