Recently I took the heads off my truck to replace some faulty lifters and put new valves in, but while replacing all that I took the whole wiring harness out and replaced some plugs and other broken clips. I got the truck put back together yesterday and when I went to build oil pressure nothing in the truck except the dome lights and headlights would turn on. Electrical work isn’t my strong suit and I’m not exactly sure where to start or if it could just be some bad fuses. Any advice would be greatly appreciated!

 

It helps if you completely identify what you're working on...

Most likely, something important is still disconnected.

 

There's like 3 wires that connect to the positive battery terminal and there are a bunch of grounds toward the back of the battery on the firewall near the PCM.

I'd guess that something like that is loose or disconnected..take a look around the battery for loose wires.