When I bought my 04, the previous owner, took out the original headlights, replaced with aftermarket, and cut out the original wiring harness. I bought factory replacement headlights to put back in, I need to buy the factory wiring harness. Need help

 

What kind of truck are you working on? 2004 has either the old body style (heritage) or new body style.

We can see this stuff through the Internet...

 

Heritage body style

 

Just buy this and solder it in:
https://shop.advanceautoparts.com/p/...E&gclsrc=aw.ds


If you don't know which wire is zero volt rail, high beam, low beam, you can get a meter and see which one has voltage when you apply the appropriate light.

Here's diagram: