Trailer Turn Signal Only Works when Brake Pedal is Pressed on 2004 Toyota RAV4

Question:

I installed 118389 on my 2004 RAV4 and my passenger side light on my snowmobile trailer doesnt blink, but does when I step on brake. all lights on car work fine. I have used trailer with two chevy Silverados and work fine. also I double checked ground twice. I installed the wiring harness according to video.

asked by: Paul

Expert Reply:

If the lights on the trailer are working fine on another vehicle, then the issue is most likely with the RAV4 wiring harness, # 11839. To test it you will need a circuit tester such as # PTW2992. You will need to have someone sit in the RAV4 and run through the various light functions while you test with the circuit tester. I have included a link to a video showing how this is done.

If you have the same or a similar problem when testing, then the issue could either be inside the converter or it could be that you need to move the converter box ground wire to a different location.

Different vehicles can compensate for a weak trailer ground connection which, if you test the RAV4 wiring and its fine, could be why it worked with the trucks and not the RAV4. There are some things you can check and try to remedy this issue.

Start by making sure the main ground and grounds for all of the lights are attached to clean and corrosion free bare metal surfaces. Also make sure the trailer connector is clean and corrosion free.

If the trailer has an aluminum frame, tilt bed, or folding tongue, any of those things could interrupt the ground. Running jumper wires from the light grounds to the main trailer connector ground can help.

expert reply by: Michael H