Brakelight Switch

[Ieatcamaros]

I have this issue on our 2003 v6 mustang. It only has 21,000 miles on it and this is too soon to be having issues with the car. Anyway, about a year ago, I was following my wife home and I noticed that she must be a hell of a driver cause she wasn't using the brakes at all. Or, they weren't working. So when we got home, I checked everything out. It turns out that where the wire was crimped in the spade terminal had broken off. Of course it was one of those special f*cked up ford connectors specially made to fit the brakelight switch. I just cut the wires and put my own insulated female spade connectors on the end of each wire(2) and slipped them onto the brakelight switch connectors. Problem fixed. I knew that is what ford would do and hold the vehicle for two weeks and also have that listed on the vin for that car when people look it up. Especially because it was under warranty. So fast forward to now. The car is 3 1/2 years old so it is not under warrranty anymore. We went to walmart this morning and we both could smell something that smelled like burning plastic. It was clear that it was fresh and inside the car. We smelled it again on the way home. When we got home I began to look for melted connections or wires or something under the dash. It didn't take me long to find that one of the wires at the brakelight switch had been hot and started to melt. So this makes me think that there is a short maybe internally in the switch. The first thing I did was take off the switch and check for continuity between the two posts. None. That made me check for continuity between the two wires. Lots of resistance. 552 to be exact. So there must be a place where they have shorted against each other. I began to hunt. I took panels off, pulled the carpet back only to find that the two wires lead to a plug and then to the fuse box. There are no places in between the brakelight switch and the fuse box where the two wires could be shorted together because I have separated them to this point. I have green wire and a red wire (leave the stipes out for now). The green wire goes to the + terminal on the switch. BTW, I did hook them up right when I fixed the broken wire problem a year ago. Anyway, the post for the red wire is not labeled. So I thought this has to be ground. Wrong. I grounded that and hooked up the 12v green wire and shot the fuse. I thought that the switch only transmitted voltage to the brake lights when the pedal was pushed. Just like any ordinary switch does. Apparently I am wrong here too. The green wire shows 12.60 volts and then when the switch is activated (pedal pushed) the voltage goes to zero and the red wire begins to show 12.60 volts. What's up with that? So my question is can anyone explain the way the brake light circuit is supposed to work on these cars? Does anyone have some schematics for these newer cars? Any help is appreciated. Sorry so long, but I had to tell the whole story for it to make sense.

Edit** it was the red wire that had melted insulation.