Brakes lights not working all three?

OK, the turn signals and brake lights share the same grounds so that isn't the issue. Do both marker lights work on each side? For the brake lights there are 3 fuses total. One is in the under hood fuse box, a 25 amp stop lamp fuse. It sends power to the stop lamp switch on the orange wire. When you step on the brakes it relays power to the white wire. The white wire feeds power back to the electronic flasher module in the interior fuse box and that then sends power out to the chmsl and stop fuses in the interior fuse box. Take a test light and check the fuse under the hood. Then hold the brake down and check the two fuses in the interior box. They only get power when the brake switch is depressed.
There are two switches for that truck, one fits the adjustable pedals and the other is for the fixed pedals, they are not interchangeable. The connector wiring plug shows the differences in the wiring, if the wrong one was used it can do damage by sending power to the wrong places. So check if you have the correct switch first.
#25771554 - WITHOUT adjustable pedals
#15128592 - WITH adjustable pedals.
If you look at the plug you should find one orange wire and one white wire, where they are depends on which option you have. However the orange wire should have full time power from the fuse. The white wire carries that to the electronics. You should be able to put a jumper between them and if nothing else is a problem the brake lights should work. If they do not then it's likely the interior flasher unit failed.

When you press the brake pedal down do you get power to the white wire at the brake light switch? This guide can help you test it

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Please go over this guide and get back to us.

OK no power to the orange wire, use a test light as Ken suggests to check both ends of the 25 amp fuse in the under hood fuse box. It feeds that orange wire. It has power full time so with the key off the fuse should have power on both ends. If it does and you touch the light to the orange wire on the brake switch and find no power, the orange wire is broken somewhere. Usually they fail at a crimp or an area where they rub on something.
Check for power and if you wish you can test the rest of the circuit by applying battery voltage to the white wire, the brake lights should come on. If they do then the problem is between the fuse box and the switch.