Brake lights will not turn off with brake switch removed

Tiny
CHRISTOPHER.HAYNER
  • MEMBER
  • 1995 FORD F-450
  • 7.3L
  • V8
  • 2WD
  • MANUAL
  • 215,000 MILES
 Hello, I'm working on the truck listed above F Super Duty. Single cab flatbed dually. I installed a 7 way trailer plug and wired it to the rear lights wiring. I also installed a brake controller. I have everything wired up except the red stoplight wire on the brake controller that goes to the cold side of the brake light switch. The problem I have is when I finished wiring everything, and hooked the negative battery terminals back up; my brake lights (all 3) stay on with the truck off. I unplugged the brake controller and took off brake light switch/removed the brake light switch connector and the brake lights are still on. I did notice that there is only one green with red stripe wire running to the brake light switch connector from the main harness and that wire coating is melted. I bought a new brake light switch and connector today. This new connector has two wires, a green and green with red stripe. Not sure if I wire both wires from the new connector to the single green w/red stripe coming out of the harness? Not even sure if the wire is the problem.
Thursday, August 20th, 2020 AT 2:48 PM

5 Replies

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Did the kit come with instructions and a wiring diagram? If so, can you post those so that I can take a look at that and the wiring diagram for the truck and see where we may have the issue? Clearly a connector and controller are pretty straight forward for wiring but some are a little different so we just need to see what they are saying needs to happen and we can go from there. Thanks
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Thursday, August 20th, 2020 AT 5:00 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good evening,

I just wanted to throw in my 2 cents.

If you have a melted connector, this means you have wiring damage from there back to the lights.

https://www.2carpros.com/articles/how-to-check-wiring

You will need to uncover the harness and check the harness. Chances are you have wires melted together from something done during the installation of the controller.

Roy
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Thursday, August 20th, 2020 AT 5:48 PM
Tiny
CHRISTOPHER.HAYNER
  • MEMBER
  • 2 POSTS
Thank you gentlemen for replying. I believe I fixed it. At first look I thought there was only one wire running to the connector. I tracked it back a little further and discovered it was two wires. When they melted it looked like one green with red stripe wire. I cut off the melted wires and spliced the new connector in and plugged the connector to the brake light switch. Everything seems to be working as it should now. Thanks again.
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Friday, August 21st, 2020 AT 8:14 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Okay. Great news. Glad you got it resolved.

Thanks for jumping in Roy because I am not sure why I missed the fact that it melted. I guess I was reading too fast last night.

Thanks for the update. Please come back to 2CarPros next time.
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Friday, August 21st, 2020 AT 8:25 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good deal. Glad you found it.

Roy
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Friday, August 21st, 2020 AT 8:38 AM

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