I am having a crisis [my nerves are shot]; my center tank stopped working and will not work at all; it's full of gas. my rear tank shut down yesterday while I was driving, then ran normally; just around the corner it shut down altogether, we had to coast into gas station [think gauge is going, it read 1/8 tank], put 3 gallons in, runs fine now. Let me preface this by giving some history, to see if it would explain what I am experiencing.
bought truck used in 2007, keep both tanks full, engine & trans good condition, all fluid levels ok.
upon last filling of both tanks, added STP gas treatment & Octane Booster to each tank. one week later, front tank stopped operating while my husband was driving. This morning i took truck to Autozone for scan, my data link didn't work, so couldn't get any codes; have no idea about fuel pressure. tried to switch FUEL RELAY FUSES myself to see if one was bad, but I don't know if I acutally found them or not...I have found two fuse boxes, driver's side next to fire wall comprised of many fuses and one little box that reads RELAY 1, RELAY2 [i exchanged fuses but noticed no change, truck would stall out on start both times when running on rear tank, switching to center tank] inline filter cannot be problem because both tanks would shut down. I need a diagram of all fuse panels/boxes, so I can try to find problem; hoping it's a $10 [fuel relay fuse] instead of $532 [for a new pump, etc installed and guaranteed]. If you have any suggestions, please don't hesitate to pass them on to me. Thank you

 

Talk to Bill; AKA Subford.......He has all the wiring crap on here....

 

The little box that reads RELAY 1, RELAY2 is for when you pull a trailer.
Sounds like all of your fuses are OK.
Hard to tell if you have a fuel problem or a distributor problem.
Autozone can not scan your truck as your truck is an OBD-1 truck with the scan port under the hood and Autozone can only scan OBD-2 trucks.
Get a $30.00 scanner at O'Reilly auto parts like this one:


Fuel wiring:


/