Engine will not crank or start?

Hello, the F15 25amp fuse is "hot at all times" so it's a memory circuit for the TCM, the circuit splits into 2 sections at Splice S107 then goes to pins 1 and 2 of the TCM connector C175A, Its a blue wire with a white stripe the entire way to the transmission module, I would unplug the TCM connectors to get it out of the circuit. And since there's a permanent short to ground on that leg of the circuit, you can hook a test light to battery positive, With the Fuse 15 removed, this way you have that circuit isolated from everything except the short to Ground. Then touch the test light to that Blue/White wire, and it should light up due to the short to ground. Then you can do a wiggle test of the harness until you see the test light flicker or go out, and you'll know what section of the harness the short is in. It's going to most likely be on a contact point where the harness is resting on a section of the frame or body. There is also a connector in series you can disconnect to isolate it more. C134, which Ill post the diagrams for.

Here are the diagrams for that circuit coming off the F15 fuse. If you have the TCM connector C1750A unplugged and touching the pins 1 and/or 2 with a test light or back probe the connector so you don't spread the TCM connector pins and the test light will stay in place while checking the harness, you can unplug the C134 connector to see if the test light goes out, if it does, then the short circuit is before the C134. If the test light stays bright then the short to ground is after the C134 connector. Just try not to move the harness around much until you have the TCM connector unplugged and test light in place. If you move the harness around, you may move the shorted section away from the damaged area and not be able to find the short after. The TCM connector diagrams are included below, let us know what you find.
Hopefully this helps.

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

https://www.2carpros.com/articles/how-to-check-wiring