Both Turn Signals Blink When the Turn Signal is Used  

Question:

Expert Reply:

You most likely have either a short in your wiring or your two circuits are touching somewhere. What you will want to do first is to test the wiring harness on the back of your tow vehicle, you can do this using a Circuit Tester, part # PTW2993. I've linked a video that will show how to test a 4-Way trailer connector with a circuit tester.

If you test the vehicle side trailer connector and find the problem to be on your vehicle, then there are a few things that you can try. You can check the wiring on your vehicle to make sure that it isn't pinched, cut, or damaged, and you can also check to see if your vehicle uses a converter box, like the Hopkins part # 119190KIT does. If your wiring does use the converter box, then it is possible that the converter box could be malfunctioning and causing the signal to cross over. You can use the circuit tester to check the signal on each wire going into the converter box to ensure that the signals are reaching the box. If the signals are going into the box correctly, but not coming out correctly, then there is something wrong with the converter and the wiring harness will need to be replaced.

If you test all of the functions on your tow vehicle and everything is working fine then you will want to move on to the trailer by inspecting the wiring harness and the wiring on it to make sure it is not corroded or damaged anywhere.

If you follow these steps and cannot find the problem or solution, let me know what you come up with and we can do further troubleshooting.

expert reply by: Jon G

0

Razz

1/19/2020

I had no lights at all on back of truck put a new ground wire to frame now have brake lights and running lights and turn signals but when you turn on driver side turn signal both turn signals come on at same time but when you turn on passenger turn signal you have nothing what could be the problem

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Jason S.

1/20/2020

It is likely still a ground wire issue. I recommend using a circuit tester like # PTW2992 to make sure you have power going to your passenger side light when you turn on that right blinker. If you do, then you have a ground wire issue with some bleed over connecting to that driver's side. You need to isolate that power left to right and make sure each light has a bare metal to metal ground free of all corrosion and debris. You can trace the wire as needed probing it to determine the origin. It may be all the way at the switch or it may have a place along the way where the wires have crossed and power changes from one wire to another.

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