2008 F350 V10 Bucket Truck Fuel Problem

[Crystal City Signs]

I have a 2008 Ford F350 Super Duty Bucket Truck  (6.8L V10)

 

Recently started losing fuel while driving.. sputtering intermittently.     Stalled occasionally.   

Discovered the inline fuel filter  was rusted out and leaking.  (The filter is located a little bit behind the driver side door along the frame underneath) 

I replaced that.. and after a minor mishap where one of the old quick connectors was failing and also replaced, the truck drove without issue for several miles.   

20 miles into a 50 miles trip it stalled once... restarted and worked fine to our destination.   

 

We made it 10 miles on the way back and it stopped altogether.       went and bough a new pump and changed it on side of road (has an access panel to easily change the in tank fuel pump)

 

Truck fired right up and made it about 20 miles before problem came back and we towed it back to our workshop.    

 

Any ideas where to start? 

Is it possible the new filter got clogged up from changing stuff out? seems unlikely  which I think would mean either the relay, or a bad wire maybe?  Any insight or thoughts are appreciated.

 

I believe the fuel pump relay is built into the engine compartment fuse box and requires replacing the entire fuse box (which sounds like a pain)    Is there an easy way to test the relay?   I saw somewhere online to check for voltage on a green and yellow wire while cranking and I assume that wire is on the fuel pump connector but if anyone can elaborate that would be awesome.  

 

Thanks in advance.