I bought a 07 4.0 Ranger a week ago. drove it 50 miles back home with no issues. Tuesday I was driving back from work and my truck just died. So I get out to see if any relays or fuses came loose since I could not hear my FP priming. Get back in my truck after 5 minutes and it starts back up and drives fine. Next morning it does the same thing at about the same distance ( Around 30 miles) and again on my way back from work at the same distance. So I decided to look, I found the inertia switch to be missing and two wires spliced together shoved in the fuse box. Could this be my culprit? Why would it just randomly shut off around the same distances. I also have a hard time filling my tank with gas, due to the nozzle constantly clicking. When the truck dies, I get evap purge valve stuck closed, FP secondary circuit High and FP secondary circuit low, and multiple cylinder misfire. Any help is much appreciated.

The two spliced wires are brown/white Purple/White/

 

Welcome to the forum

Simplest first
Your Vent hose in the filler neck of gas tank is blocked/kinked
For gasoline to flow into the gas tank air must be able to get out, so there is a Vent hose in or next to the filler hose to allow air out.
If air can't get out the gas station nozzle will click off because gas is backing up in the filler tube.

Inertia switch should be reinstalled, but not your problem

Try loosing gas cap and driving to work, so air can get into tank
If EVAP is an issue the gas tank may be building up too much negative pressure inside so fuel pump simply can't pump out fuel after a certain amount of time/miles.
Letting it sit allows gas tank pressure to equalize so restart is possible

Misfires are when fuel pressure is dropping
FP circuit issue could be FP drawing more amps try to pump out fuel.

Or whole thing could be computer issue, but test the easy and free stuff first, lol

 

Tried what you stated above. No change sadly. Fuel pump runs no matter if my key is pulled or the relays are pulled and I'm getting 16 volts to the fuel pump somehow. I'm stumped. I still have gauges and Spark when this happens.

 

If engine was running when you got that 16volts then alternator needs to be replaced, for sure.

If you got the 16volts with engine off then volt meter needs to be tested

New battery can be as high as 13volts, most are 12.5volts after a few years use

Engine running voltage needs to stay below 15volts
13.5 to 14.8v is spec for voltage regulator inside alternator

Reads like previous owner may have done some "rewiring" you will need to track that down to see what he/she did
Some people do oddball wiring on fuel pumps for theft prevention, i.e. cut off switches