3rd Brake Light

[wagonman76]

I like the idea of a 3rd brake light. Usually there is no easy surefire way to integrate it. Can use a 9 wire plug or extra connector, which I did on my old car and trailer. Or use the JC Whitney logic circuit but it isn't all it's cracked up to be. I once even tried a keyless entry I had laying around to send the car brake signal to the trailer, that didn't work well.

Well my Hydrastar has a nifty little circuit board inside to take the varying brake controller voltage and convert it into something constant to fire a relay, to disengage the drainback solenoid, while still not firing the relay with the diagonstic voltage from the brake controller. Well they were nice enough to build in an extra wire coming from the normally open side of the relay. Perfect for firing a 3rd brake light. Also I could put in diodes so if the trailer ever came loose and pulled the breakaway pin, it would light the main brake lights as well as the 3rd brake light.

If I knew more about electronics, I could duplicate this circuit and make any standard brake controller do this even with plain electric brakes. I couldn't read anything off the parts because they were surface mount and very tiny, but it was a very simple circuit.

I mounted the 3rd brake light to a piece of stainless steel that is screwed to the bathroom window trim using two of the existing screws. The wire runs into the bathroom window in a way so it doesn't leak, down the corner of the wall, and down thru the floor.

[JohnB]

Hi Wagonman

Good deal and yes the extra light helps.

On mine I have added 2 extra brake and signal lights as my rear boxes are about 18” from the back of the TT. On the newer campers Sunline ran the tail and body light harness on the bottom of the camper, outside the waterproof membrane then up into the wall to the rear lights. In my case it was easy to tap into the wiring. I just skinned back the insulation, never cut the wire, soldered on the new lights feed and taped it back over.

I do not know how the older models where wired up. I think they have sheet metal on the bottom and the harness may be above that.

John

[Steve Collins]

I added a pair of 6" oval LED fixtures directly above the existing tail light fixtures. They are a surface mount model, and I fabricated a backing piece for each one out of 1/8" ABS so that there was a flat surface to caulk.

One of my sons gave me a receiver mount brake light a couple of years ago. They never seem to work well because they come with a a four pin plug to grab the regular trailer wiring so you get either a left or right brake/turn, but not both. I tapped the truck's CHMSL (center high mount stop light) and ran an extra wire back to the receiver for the brake light. It will now be easy to run a pure brake light line to the rear of the TT and up to a fixture above the rear window.

[wagonman76]

Originally Posted by Steve Collins

One of my sons gave me a receiver mount brake light a couple of years ago. They never seem to work well because they come with a a four pin plug to grab the regular trailer wiring so you get either a left or right brake/turn, but not both. I tapped the truck's CHMSL (center high mount stop light) and ran an extra wire back to the receiver for the brake light. It will now be easy to run a pure brake light line to the rear of the TT and up to a fixture above the rear window.

Steve, it sounds like the receiver brake light uses a logic circuit like that JC Whitney one. There is no surefire way to get a real brake signal with just a 4 wire harness. On my old car I used the CHMSL signal to go to one of the extra pins in the 9 wire plug. (On an older car with no CHMSL, you could just go off the wire at the brake pedal switch, that's where they tapped for the CHMSL anyway.) Actually I liked the 9 wire plug better anyway because it is the same size and shape as the 7 wire, but is much more solid and secure because it uses round pins instead of blades.

Originally Posted by JohnB

On the newer campers Sunline ran the tail and body light harness on the bottom of the camper, outside the waterproof membrane then up into the wall to the rear lights. In my case it was easy to tap into the wiring. I just skinned back the insulation, never cut the wire, soldered on the new lights feed and taped it back over.

I do not know how the older models where wired up. I think they have sheet metal on the bottom and the harness may be above that.

John, at least on mine, it is assembled just like you say. There is a black waterproof membrane on top of the steel frame, and the camper is built onto that. The wiring and gas lines go below the membrane so it is easy to get at. I just ran one wire from the extra Hydrastar wire and bundled it with the rest of the harness. The ground I attached to an existing frame ground that was very close to where my wire exited the floor.

[wagonman76]

Here's the light off and on. I took the covers off my clearance lights for the winter because they kept wanting to fall off. A little dab of caulk each should keep them on.

This is also before I fixed the screen in the window the vandals broke out, that's why it looks so light.