All Lights on Truck and Trailer Blink After Installing New Trailer Lights on 1988 Scamp Trailer

Updated 02/21/2013 | Published 02/16/2013

Products Featured in This Question

Optronics LED Transit Tail Light - Stop, Tail, Turn - Submersible - 31 Diodes - Red Lens

(88)

$36.80

Hook Probe Circuit Tester

(65)

$13.35

Question:

I have a 1997 Dakota and 1988 Scamp I use a 7 pin round connector rear trailer wires have W=ground.. B=tail light.. R=stop.. G=turn.. I wired per your web site info as follows: trailer W to LED unit W.. trailer B to LED black.. trailer Red and Green both wires to LED Red.. Here are the rusults Ive gotten from this wiring: Tail Light function: ALL LEDs light up the center section, the middle section, and the outer section I dont think this is the correct action. Turn Indicator: ALL LEDs on BOTH units blink center, middle and outer plus the LED clearance lights I recently bought from you also blink, and if that werent enough, my Dakota front turning lights both lights and the Dakota rear lights both lights also blink.. Everythink acts like I have engaged the Emergency Blinker Switch which I assure you I HAVE NOT.. I get the same results wheather the Left turn or the Right turn are engaged. Stop Lights: Same results as the tail light function, ALL LEDs on BOTH units center, middle and outer light up.. I sure need some expert help.. please, please, please.. Thanks

asked by: Kenneth M

Expert Reply:

On the Transit LED Stop/Side Marker/Tail Light, # STL90RB, only the outer ring of LEDs and the center circle illuminate with the tail light function. The middle ring is a reflector, not a light (see photo). When the stop or turn signal is activated, only the outer ring should illuminate with a higher intensity, not the center circle, I made a short video for you showing how this light should function.

Based on your description, it sounds like your trailer has a 3-wire setup rather than the more typical 2-wire setup. The 3-wire setup uses separate wires for the brake light function and the turn signal functions. Is this how your trailer is set up?

Also, if you disconnect the trailer from your Dakota, do the lights on your Dakota work properly? If so, power is somehow back feeding to the trucks tail light circuits. This could also be related to the reason that all of your lights on your trailer blink when you activate your turn signal. I would first recommend

To begin troubleshooting the issues, I would first recommend checking the ground connections for the vehicle side and trailer side connectors. They should be grounded a clean, bare metal surface on the trailer or vehicle frame. Poor ground connections can cause many different problems. I would also check for any damaged wiring insulation that would allow different circuits to touch each other. Wires could also be touching inside the trailer connectors. This could explain why all of your lights blink when you activate only the left or right turn signal.

Once you verify there are no ground issues or damaged wiring, remove the Transit LED lights that you installed to test the wiring. Once the light is removed use a circuit tester like part # PTW2993 to test the function of each wire on your trailer. You do not want to connect wires by color because trailer manufacturers do not stick to an industry standard color code. The wires on the Transit LED light are white for ground, black for taillights and red for stop/turn signal. Once you verify which wires on your trailer are for which functions, wire the taillight accordingly.

If you are unable to find the problem or a solution after following these steps, let me know what you come up with and we can do further troubleshooting.