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Adding turn signals: Calling all Electrical/BCM experts


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What's the easiest way to tap into the turn signal(s)?

 

I installed amber LEDs onto the side of my tool box/back rack with one functioning as a running light (tapped into 7 pin) and the others as turn signal(s) I had originally planned on splicing the turn signals at the harness but realized the green/yellow wires also send brake signal and therefore would light up the turn signal LED's anytime I hit the brakes. I referenced the BCM wiring diagram and tapped into the front turn signal wires.

 

Turn Signal (Left) blue/white (F); yellow/blue ® + BCM under driver dash, brown 26 pin plug, pins 2, 1

Turn Signal (Right) green/purple (F); brown/green ® + BCM under driver dash, black 26 pin plug, pins 3, 4

 

 

All was fine for 2 weeks, running lights and turn signals worked perfectly. Today, when I turned the truck on and used a blinker, I got the dreaded "hyper flash" and DIC message indicating I had a front turn signal issue. I've pulled the wires from the BCM while I resolve the issue.

 

My questions are as follows:

 

1) What/Where is the best place to tap into the turn signals. I'm only running 1 x 6" LED per side, I can't imagine the draw being that great, although from other threads, I know the BCM is a fickle beast.

 

2) Would installing a diode (Fogs/Highs - Reverse/Cargo) between BCM and the hot/"+" for the LED's help if the BCM is the best place?

 

3) OR: is the "hyper flash" issue something that could be resolved with load resistors which are the from all post issue research are design to eliminate this problem, traditionally in headlights where LED bulbs are swapped in.

 

 

 

And of course, because every thread is worthless without pictures, here's the truck with the amber running lights on.

 

running2

running1

 

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Make it easier on yourself and run everything off the trailer wiring harness. I've done the same, added multiple extra turn signals, backup lights, brake lights etc because I tow big and heavy., all wiring off the trailer wire harness with no issues, and every light is LED and hardly any draw, not even an amp when added together.

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Make it easier on yourself and run everything off the trailer wiring harness. I've done the same, added multiple extra turn signals, backup lights, brake lights etc because I tow big and heavy., all wiring off the trailer wire harness with no issues, and every light is LED and hardly any draw, not even an amp when added together.

 

I tried this. Unfortunately the 7 pin and 4 pin connectors both have common L/R Brake/Turn Signals. So that even though the blinkers work, when i hit the brakes they are constant on. How did you get separate/dedicated turn signal feeds off the trailer wiring?

 

I've looked into devices from Curt(56196) and Tow Ready(118158) that take the 4 pin signals and give you dedicated turn/stop signals. ** Edit: there's a review on amazon from a guy with a K2XX who installed the Tow Ready converter and ended up with alternating blinker signals when the brakes ware applied.

 

 

when you had the hyper flash did the front and led hyper flash together or did they alternate between each other

 

I had tapped into the rear signals at the BCM. DIC showed driver side rear taillight failure , hyper flash was synced but sometimes the toolbox light didn't work at all (faulty light?)

Edited by TheTunaHunter
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  • 6 years later...

Did you ever figure it out? Plan on making the outer lights on my “Raptor” style grill flash with turn signals. Can’t seem to find any info on this except tap into the trailer wiring. I don’t want to run a wire from the back on the truck all the way to the front though…

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