Now that I have everything plugged back in again I can't get power to the inside of the car. I have all the grounds connected that are on these specific harnesses, the only harness I'm missing is the engine harness right now for obvious reasons. Any help is appreciated
I'm assuming that you have confirmed there is "always on" power inside the fuses of the Battery Junction Box(BJB=F1). Right?
Next, double check that the CCRM/PCM ground that connects to a large round single pin connector. The black wires and black wires with a white stripe (BK/W) that goes around the battery and onto the radiator core support/battery negative.
Double check that the two grounds on the left hand radiator core support are in place as well as the battery negative ground.
There's also another ground on the right hand radiator core support. It's easiest to see under the air cleaner.
But the biggest grounds runs THROUGH the engine! There's a very large ground going straight to the block. Plus there's another grounding strap that goes from the left hand motor mount to the frame rail. With the motor removed that ground path does not exist.
Do you want to rule out some possible causes? Test all of the BK/W wires on the CCRM for the ability to carry a real current back to battery negative. Use a test light that will "load" the circuit.
Confirm there is key on power into and out of fuse F2.34. If no power suspect an ignition switch problem.
Confirm there is key on power into and out of fuse F2.2 and F2.8. If no power suspect that the CCRM is not "latching" up.
Do the head lights work? If not suspect no power inside the BJB (you did check this right?). Or main ground is no good. 1999-2004 MY fuse panel schedule: https://www.allfordmustangs.com/foru...ml#post2669271 1996+ Crank with no start check list https://www.allfordmustangs.com/foru...e.html#2984838 Howto perform charging system voltage drop test https://www.stangnet.com/mustang-for...-drop-test.56/