After writing the Be Seen blog post back in February, I found myself revisiting the notion of adding a higher level brake light to my Teardrop camper but once again stuck with the limitation of 4-pin wiring which is standard on small trailers. Thanks to a chance find at the local automotive store I was able to jerry-rig a solution!

4-Pin Trailer Wiring

This is the most basic system of trailer wiring, and pretty standard on small utility and boat trailers, as well as little Teardrop campers like mine which are essentially a cabin structure custom-built onto a standard trailer frame. The tail lights on the trailer have two inputs to bulbs (or LEDs):

• running lights (brown wire) which are constantly illuminated when tow-vehicle’s headlights are on, as well as a near-useless light for the license plate
• brake/turn lights (yellow & green wires) which EITHER illuminate constantly when braking OR flash along with tow-vehicle’s turn indicator.

More Lead-time, Better Safety

I wouldn’t say the standard small trailer tail lights are any big attention getter. For one thing, sometimes they’re not too bright, or just cheapo lens plastic. But more significantly, they are generally positioned quite low since they’re part of the trailer frame.

Adding a centre third brake light (aka High-Level brake light), like what we see on most vehicles, can make it more obvious to traffic behind the trailer that you are slowing or stopping. The problem with adding such a light to a 4-pin wiring system is the dual-function brake/turn light circuit because the third-brake light would also flash whenever the turn indicator is in use.

MacGyver to the Rescue

I did a lot of looking around online to see if I could find a third-brake light engineered for 4-pin systems that might have some sort of electronics to basically ignore a flashing signal but pass-thru a solid light to the brake lamp. No luck. But then at my local Princess Auto (a Canadian chain which has everything you can imagine and more) I came across this lighting product. It is intended to be added to stowage accessories using a trailer hitch, like a cargo rack or bike carrier, that may obscure vehicle tail lights.

Used as intended, it plugs right into the vehicle’s 4-pin plug. But I figured it wouldn’t be difficult to figure out which wire lead to what and splice it in to my trailer’s wiring. Each light strip has two sets of LEDs, one for running lights and a second for the dual brake/turn function. The light are 7″ long and narrow enough they could be positioned on the rubber joint strips at either side of the galley hatch.

The teardrop’s rear is of course rounded, while the strips are not (nor flexible) so I affixed it to the trailer by building up layers of double-sided Gorilla tape under the ends of the strips and then applied black caulking around the edges to keep it more firmly in place and provide a weather-proof and smoother look.

For now I left the wires external, leading down to where they are attached to the trailer wiring. But eventually, if it holds up over time, I plan to re-route the wires into and down through the black rubber joint strip which has a channel below it.

So, that’s how I do things with my Teardrop Trailer but by no means the full story or the best way. What about you? Add your own methods, ideas and experiences using the comment box below for the benefit of all readers.