so to test this could it be wired around bypassing the wiring behind where the white/blue ends?

[QUOTE=patrickoneal;5433640]Here's the details. As the original post says, the white/blue wire from the bed switch is supposed to run all the way to the white/blue wire on the headlamp switch on the dash. It seems to stop at connector C316 under the hood.

It needs to go from here(White/Blue wire Pin 31 out of 34, fourth in on bottom row):




To here(my headlamp switch already has some splicing from my remote start, so yours will look a little different, pay attention to the white/blue wire only):




I used one of these posi-taps to tap the wire under the hood:




I used 20 AWG wire, as it was the smallest I could find locally. O'Reilly sells it for $0.19/ft and had it in white. The factory wire is 22 AWG, so 20 is fine. I wouldn't go bigger, it was hard enough to fish through the boot.

I was able to fish it through the boot under the hood by taping the wire to a cut off zip tie. I did not have to cut off the zip tie around the boot under the hood, but I did have to cut it off under the dash to fish it though. The under dash boot was re-zip-tied and taped after the wire was ran.

Tap installed:




Here's the wire ran through the outside boot:



Here it is inside through the boot and tied up to a harness(you'll likely have more room if you have an electric parking brake):




Here it is soldered to the white/blue wire on the headlamp switch, I think a posi-tap would fit back there as well, I just prefer solder. I unplugged the connector before soldering to avoid applying any heat to the switch:




I insulated it with vinyl electrical tape, then followed up with cloth Tesa tape to re-cover the harness and attach my new wire to my aftermarket remote-start harness. You can zip-tie or tape it to the headlamp harness if you like:




Here's a finished view under the hood:



And the "fish tape" made from a zip tie:




On my 2018 STX SuperCrew both wires were missing at connector C316. You most certainly have the white/blue wire in slot 31 and green/blue wire slot 30 of 34 on the side facing the driver.
The other side is where it may be missing. Instead connecting to the headlamp switch I used the the taps at Connectors C238

To look at it I did the following:

1. Disconnected the battery.
2. Carefully pried up the connectors, there's two christmas tree type retainers holding them down.
3. Lifted the bail to separate the two halves.
4. Carefully tapped the wires facing the driver on connector C316
5. Ran the two wires troughtout the fire wall plug and tap the wires at connector C238 instead of the headlamp switch
6. Connector C238 is right behind the left side kick panel right by the hood latch release looks white and green
7. Tapped the new two wires at the famele side since is the side that has the two actual wires we need to active the Bed Cargro trunk lights

You may not have to pry up the clips like I did. I can't remember which side of the connector is fixed to the fender with the retainers.

It’s been a while, but I think you’re right.