Brake light switch harness melting

I just needed to know which wires are pos n neg out of LG/RD. An GRN

Thank you bretb for your response. The wire in question is the LG/RD wire from the fuse panel that continues to melt the harness connector. The current draw is 3.7 amps with the brake pedal applied. The new pigtail has been installed per the directions stated in the TSB. The only difference between the old and new harness is the original harness is made with 18ga. wire and the new one is made from 16ga. wire. I have returned the car to the customer after tightening up the terminals and replacing the stop light switch until I can try to come up with another solution. Thank god for tolerant people in this day and age. If you need more info, I can call on them to come by for further testing. Gary

Gary, It sounds like the 18 gauge wire was not able to handle the current, although it should handle 4 amps without a problem. The fact that the new harness has 16 gauge wire leads me to believe this might be a common problem. Do you think there are some driver habits that are contributing to this? Resting their foot on the brake? Is it possible there is an amperage spike after the brake has been applied for awhile? Anyway, glad to hear they are working with you on this, you sound like a very thorough and professional tech. Keep up the good work, let me know if this fixes this problem, and feel free to ask any other questions! Bret

Thank you for all your help with this issue. After seeing the new harness that Ford sent me per the TSB, I thought the same thing about the gauge of the wire and also felt certain that this would resolve the problem. I will talk to my customer about "his wifes" driving habits to verify. I will also have them stop by for another current draw test to see if there could be a spike after applying the brakes. Thank you again and will let you know the outcome. Gary

Ive had the same issue, now for a while, the cable keeps wearing down from the burn. I just added 10 gauge to the tip the what seems to be original red cable is getting shorter and now it may start from where i attached the 10 gauge, not sure whats the problem. i know the pedal stays up and unless its something thats weared out and the pedal is slightly weighing down to activate the switch, but the brake light doesnt stay on by tis self though. Gonna try switching the cables, the other cable seems to be just fine.

I posted that last one aswell, thank you if anyone has anything on this issue relly annoying. Im going to get the book from my friend too so i may see whats the wiring looking like to test the amperage........ respectfully with humble patience, jose

i have the same melting problem on my 1998. got to switch it again thanks.

I have the same issue, the wires to the break switch get hot and melt everything. Does anyone know what causes this? I replaced the break light switch but the wires keep getting hot.

did anyone ever get a real solution to this problem ? i need help i have did all of this still melting