2 to 3 converter trailer 3rd brake light

Printed From: the12volt.com
Forum Name: Lights, Neon, LEDs, HIDs
Forum Discription: Under Car Lighting, Strobe Lights, Fog Lights, Headlights, HIDs, DRL, Tail Lights, Brake Lights, Dashboard Lights, WigWag, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=124494
Printed Date: May 14, 2025 at 2:54 AM

Topic: 2 to 3 converter trailer 3rd brake light

Posted By: bwanna
Subject: 2 to 3 converter trailer 3rd brake light
Date Posted: November 16, 2010 at 7:23 PM

Hello,

I've searched the internet and this site for a circuit (probably diode based) that will convert a 2-wire setup on my trailer so I can add a third center Brake light and independent Turn Signals. So far no luck.

I know Hopkins sells a kit that I'd like to mimick. (https://www.etrailer.com/Tow-Bars/Hopkins/38955.html)

Was wondering if any of you ingenious types could help me figure this out?

Background. My vehicle delivers the standard 4-pole connector:

Green = Right Brake and Turn Signal
Brown = Tail Lights
Yellow = Left Brake and Turn Signal
White = Ground

Would like to have the following outputs converted from the above 4 lines:
1 - Brake Only
2 - Right Turn Signal Only
3 - Left Turn Signal Only

Thanks!!!

Replies:

Posted By: oldspark
Date Posted: November 17, 2010 at 6:16 AM

Not that I could be bothered figuring it out, but it may be based on brake = both sides or one side (stop-flasher) constantly on.
Each turn is simply a flashing signal on that side.

Alternatively, get the signals from the flasher and brake switch before it goes into the combiner (ie, brake from brake switch; left from front-left flasher etc).

Posted By: bwanna
Date Posted: November 17, 2010 at 7:59 AM

Appreciate the response. I tried the basic logic analysis u using free circuit designing software with AND/NAND type gating. Couldn't get anywhere using the you're of approach you've suggesting. Oh well. Hopefully someone will have an idea.

Posted By: oldspark
Date Posted: November 17, 2010 at 2:39 PM

Start with a plain Karnaugh map.
Then maybe consider the gating.