Trailer LED Lights Not Working when Connected to a Mazda CX-5

Question:

LED lights do not function when connected to my 2 year old Mazda CX5 I recently discovered that my 3 year trailer and lights old LED lights do not work properly. Sitting in the car they look fine, the riding lights are working but when you view from the rear when the riding lights are on, the tail riding lights and both indicators are going! When you the indicator, both the indicator light and the riding light blink. Someone suggested that this can be a fault with newer vehicle electronics and LEDs. I asked a neighbor with an older car to connect his car up and the lights work just fine. Any suggestions for trying to remedy this.

asked by: Gavin J

Expert Reply:

There can be issues on some vehicles/trailers using LED lights. Sometimes the lights don't work at all and other times weird things happen like what you are describing. It happens because LED lights draw such little power it can sometimes confuse the vehicle side of the system.

First, we need to make sure you have the proper wiring harness on your 2014ish Mazda CX-5. If the vehicle itself has LED lights I recommend using harness # 118563 which is listed for models with or without LED lights. This is a powered harness that powers the trailer lights from the vehicle battery.

On the trailer side you can simulate more current draw by using load resistors such as # DI34ZR. You would need one per affected circuit so a total of 3. I have also included a link to our help article on troubleshooting trailer lighting issues.

expert reply by: Michael H