2003 ford ranger May be a long post. Originally every time I hit a bump the fuel shut off switch would engage and shut off the fuel pump. So the mechanic that I went to bypassed the fuel shut off switch and there's no switch there and it ran fine for years. Now within the last year. Originally I went to start my truck it seems like it happens more when it's raining and when it's cold. But I went to start my truck and out of know where I had no fuel pressure. I changed the fuel pump it ran fine for 3 weeks and then it happened again so I took it to the mechanic a different mechanic. He ran a wire from the fuel pump to the battery grounded the battery off of the relay and it ran and grounded something else off the side of the inside of the truck and it ran fine for 3 months then it did it again he also replaced a bunch of corroded wires underneath the firewall but anyways he ran a wire from the fuel pump to where the fuel shut off switch was it ran fine for a few months then it happened again now he has a wire going from the alternator to the fuse box a 10 amp fuse. Every once in awhile I'll be driving and everything stops the fuel pump quits working if you put gas in the throttle body it starts every once in awhile if you wiggle around a wire it starts the mechanic hasn't been charging me he has fixed it four times for free but he says he can't figure out what's wrong with it every time he takes it back he just messes around with the wires we hook them up and it runs for a couple months and then out of nowhere shuts off. He won't tell me what he fixed because he said he doesn't know what's wrong with it he just messes with it until it starts to run again cuz I can't really complain cuz he doesn't charge me anything. He initially charged me $500 in the last five or six times I've been there he hasn't charged me anyting. I can't figure out what's wrong it is an old truck but once you get it running she runs great

 

The battery alternator and starter are all good with in a year old had them all checked at the auto parts store they all have power and are in running order

 

Welcome to the forum

What engine is in your 2003 Ranger?

Have you had the codes read?
That will tell you if power to the fuel pump is being cut off
Computer monitors that

What about dash lights
With key on the CEL(check engine light) should come on or if engine stalls CEL should come on

2003 Ranger will have an anti-theft system that cuts power to fuel pump and injectors, fast flashing "theft" light would happen for that

Power for fuel pump here
Battery-------fuel pump fuse---------fuel pump relay-----------inertia switch--------------------------------fuel pump

Fuel pump fuse and relay are in engine fuse box, the computer activates fuel pump relay AFTER engine is running, which can confuse some mechanics, key on sends power to fuel pump but ONLY for 2 SECONDS, then no power until engine is started

You said inertia switch in the cab is bypassed, missing


Without current wiring diagram I am not sure what to tell you
Its really not a complicated system when stock wiring is in place

Fuel pump needs minimum 20amp fuse, but can use 10amp fuse, depends on the wire size he used

 

Every time I stop at the auto parts store it won't read the codes and ask for the check engine light it isn't on but some of the lights don't come on it in the dash the other thing is evidently I have a wiring problem that's bad I replaced my turn signal switch three or four times in the last 3 years it always goes bad in the wiring inside melts the pigtail. And there's a constant beeping while I'm driving not all the time but once it starts it keeps beeping for like 20 minutes all these questions I've asked three different mechanics no one can figure it out the guy I've been taking it to he's a highly recommended mechanic he does a lot of work he has a big shop. Every time I come back to pick it up he just scratched his head laughs and says good luck

 

Not sure I can be of much help then

There is not one connector or even 2 or 3 connectors I can recommend looking at

You can pull up the engine fuse box and have a look at the under side, ALL power comes from that fuse box

 

The guy that works on it for me even replaced and put a new fuse box in now that I think of it. But anyways thanks for trying