No brake lights but switch is getting power

[Peanut74]

I am now in the wiring stage of my trucks rebuild. As a beginning I decided to check the brake lights first. They did not go on when brake pedal was pushed. I did check the switch out and it is working fine. I then checked the taillights for good grounds and power. They do have good grounds but no power. I next checked the harness plug under the bed. No power on any of the terminals. I did some searching here and found this "The brake lights and all other lights for the rear of truck and front run through the turn signal switch". Which might explain my issue since I don't have the steering column installed yet. Sorry for being long winded but what to make sure everyone all the information.

So my questions are:
1 = Does the steering column indeed need to be wired up before I can check the brake lights?
2 = Does anyone have a good wiring diagram that I can download?
(I have found a couple but when I zoom in I can't make anything out.)

Thanks in advance for the help