I read on a mustang forum "If you disconnect the brake light switch and the lights stay on then you have a short to power somewhere.... could be between 2 wires or in the turn signal switch. Could also be something wired incorrectly." What wires would cause this?

 

Both "switches" are really sensors that send a signal to the BCM. The BCM then sends the appropriate signal to the appropriate device. Older cars they were actual switches that just turned the current on or off to a light.

First you say no brake lights now you say they won't go off.

Please get you stuff straight.

I suggest that you put everything back to the way you found it and take it to someone that has a clue.

 

Ok so why won't the lights turn off? Something with the BCM? Because even disconnected, the sensor can't send a signal to the BCM

 

What I thought was daytime running lights, the tail lights. Now putting the hatch down I can see the its the brake lights themselves. This is all new to me like I'm trying, and I explained in the post it was hard to describe. I had my sister standing at the back, this time I had my dad so now I have a clearer answer since doing the experiment with him. I can only get straight what I actually know

 

The brake lights are always on unless I pull out the key. They only turn off when the key is taken out.

 

What about the CenterHighMountedStopLight(CHMSL)?

 

Thats in the fuse box right? I checked over all the fuses and relays again and swapped anything that seemed to affect the lights. I recall seeing that on one of the fuse/relay diagrams on the plastic covers. I think the brake lights are recent since touching the switches but I can't be certain if it is recent or has been a thing for a while unnoticed since I've been working in the front

 

The stop lights that are mounted high in the center of the rear hatch.

 

Yeah they're always on as well

 

They are on different circuits so must be the switch/wires.