Third Brake Light on Shell

[svfd]

My fire department just got a new 2019 1500 classic and had a shell installed on it. I really did not think about it when they installed, but they tapped into the driver's side brake light for the light on the shell. Now, as you can imagine, the brake light on the shell flashes with the left turn signal. Is there a good place to tap into the CHMSL wire somewhere to run to the shell? Does anybody know where the wire runs up to the top of the cab? And what color is that wire? Is there a good/easy place to tap into? I know I could tap into right at the light itself, but I don't really want to mess with the headliner to get a wire down from there. Any suggestions?

 

[Quick_Shifter]

@svfd
Sounds like you tapped into the wrong wire. Not too familiar with the 19 but the quick and easy fix is to tap into the trailer harness.
Their should be a brake light feed to the taillight where you are tapped into now so I would test with a voltmeter

 

[Gregdad]

On my 2015, there’s a white wire, tied to a loom, on the drivers side rear, that’s for a topper 3rd brake light. I used for my lighted team emblem. Doesn’t flash with signal, only comes on with headlights and brake.

 

[svfd]

On my 2015, there’s a white wire, tied to a loom, on the drivers side rear, that’s for a topper 3rd brake light. I used for my lighted team emblem. Doesn’t flash with signal, only comes on with headlights and brake.

I'll check that out. When I had a Ford SuperDuty, there was also a wire like that under the bed. I wasn't sure if Ram put something like this under there too....

 

[crash68]

On my 2015, there’s a white wire, tied to a loom, on the drivers side rear, that’s for a topper 3rd brake light.

^^^ what he said, it's a white wire with a purple strip. It powers both my topper and tailgate third brake light.

 

[Gregdad]

^^^ what he said, it's a white wire with a purple strip. It powers both my topper and tailgate third brake light.

Like this

 

[Richmond2000]

alphaobd software lists a topper 3rd brake as an output and is turned on in the options on my 2014 RAM

 

[svfd]

Never thought to look in alfaobd. Guess I need to check to see if that is an option for my year.

 

[TigreST]

This may be an option "if all else fails". I asked a similar question about connecting a receiver hitch "RAM logo brake light unit" to the factory harness. My old 03 SLT had a spare connection hiding in the right rear area of the chassis for connecting a "4 prong" trailer lighting harness or anything else you would like semi related to brake lights and such. Not so for new 2018. The solution, and a extremely clean install was the Curt Trailer harness. Here's a link to that post which shows the install to a degree. It may or may not help you with your topper brake light but.......

https://www.ramforum.com/threads/receiver-hitch-brake-light-connection.131748/#post-1908422


T.