Why does my brake wire burn in half on my 2000 mustang?

did you scan the PCM first.
rear lights dead, not dead dash brake warning light.

check all fuses first?
the fuse is in the cab or under hood
so lets find out where, i open FSM book, and look at schematic
brake lamps
the fuse is in JB box. cab fuse box.
its marked clearly as. Fuse F23 Brakes.
the brake switch is on the brake pedal.
if the fuse is good, 12vdc on both sides.at all times.
then the brake switch is open
if its output is 0v brakes pressed.
if the output is 12v then the switch is good, and the wire
are bad, to the rear.
or both lamps burned out or both sockets bad or wires cut
from trailer hitch hacks,.

Thanks for the update! This could help others on here!

1. Check fuse
2. Installed trailer plug lately, if so check wiring
3. Check switch above pedal arm

There is a switch under the dash for the Brakes. If this is the part they are replacing it can be due to physical damage caused by shoes hitting it. If you can check the repair bill find out if the switch is broken or burned out each time it was replaced.

If the switch is burning up, you need to trace the Brake wiring to the 3 fixtures. The high fixture and both taillights. Your problem would be bad light sockets or a bad wire to the brake. You are just operating about 3 lightbulbs, which at best is maybe 3 Amps. But if the power is grounding through a bad wire or bad socket, it will draw as much as it takes to melt the connection.

Don't know how important it is to you to know if your feet or someone else's feet are hitting the underdash switches. You could put ATV blue on the switch and it would rub off on the shoes hitting the switch. But it could make a mess on a carpet or start a War.

I hope you find my solution very helpful.

replace brake light switch, it's mounted just above brake pedal under dash. Small switch w/couple of wires coming from it - easy fix. (common prob)

Hello, There are small wires that attach to the Starter Relay. These are the wires Mechanics call "tickler" wires. There should not be power going through the tickler wire unless the Ignition switch is turned to the START position.

Disconnect the small wire off of the Starter Relay. Leave it off and put your battery cable on the Battery. The Starter should not crank. The Ignition should be OFF.

Now we need to find out where the tickler wire is getting power from. Put a Multimeter or test light on the Tickler wire for POS and ground the other wire on the tester to a NEG ground. I suspect your problem is in the Interlock switch. The Interlock switch would be on the Clutch pedal lever under the dash for a standard shift.

If you had an Automatic transmission, the Interlock would be in the shift linkage or Brake pedal lever. Without changing from an Auto to a Standard trans people have trouble hitting the under dash Interlock switch with their shoes getting in and out of their cars. Even while driving you can hit the under-dash switches with your shoes.

So check under the dash for a broken or dislocated switch on the Clutch or Brake pedal levers. Then move the switches until the Test equipment shows the power is not going to the Tickler
wire . Once you do this you have to make the START position work on the Ignition switch. Leave the tickler hooked up to the test equipment until you get the wiring right. You may have to adjust the Ignition shift-rod in the steering column so that START means the correct thing only in the start position.

I hope my solution is very helpful in giving you ideas about fixing your car.

have you checked the fuses for the brake lights it is in the fuse panel under the dash on the driver`s side.if it is good and only the brake lights don`t work(signals work)then the nest step is to check the brake switch.this is under the dash at the base of the brake pedal and above.when you push on the brake pedal it pushes against or moves the switch enough to close the circuit.you should see a 2 wire plug connected to the switch.there should be power on one side of the switch at all times and when you push on the pedal there should be power on both wires.one wire supplies power to the switch and the other supplies power to the brake lights.if you don`t have power on both wires then you have a bad switch.NOTE fords have a problem with the wires breaking at the switch.

FOLLOW YOUR BRAKE PEDAL ARM UP TO THE SWITCH UNDER YOUR DASH THIS WILL KEEP BOTH FROM WORKING MAKE SURE IT IS MAKING CONTACT OR THE WIRES HAVENT COME DISCONNECTED

Fuse panel is under the dash also as I have found with my own graceful daughter, there is a brake light switch that connects to the brake pedal itself. It is hard to get to and even harder to see but a lot of times these switches get bumped and they can not make connection when the brake pedal is depressed. Hope this helps

switch behind break pedal is bad, replace switch