94' GMC Sierra v8 wiring issues

[Jayp33]

Hey my name's Jay. I jus bought a GMC Sierra v8 and ran out of gas yesterday, and today after getting gas in a gas can and putting it in the truck, it won't start and I'm having trouble identifying the wires in the junction box because previous owner has it Mickey mouse and wired complicated.
HELP

 

[dbrannon79]

Welcome @Jayp33 in your photo that blue wire repair is something that someone has done to bypass a fusable link. not sure what it powers, but the relay next to the junction block right side in the pic is your fuel pump relay. the small box to the left is the fuse holder which has a fuse inside that is for your fuel pump. when you turn the key on (assuming your's is a gasoline engine) listen for the fuel pump to turn on and run for 2 seconds. if not, you will need to check the fuel pump fuse as well as all of the fuses in the cab for power with the key in the run position.

if all checks out good. have a friend cycle the key from off to run (not cranking) and see if the fuel pump relay is working. then it will be to crawl under the truck and access the harness connector on the fuel tank. you will need to check for power there.

when you turn the key to the run position the PCM will turn on the fuel pump for 2 seconds to prime the system. you can test for power that way or have someone crank on it while you test for power with a test light