Troubleshooting Lights on a Trailer With a 4-Pole Connector

Question:

I installed a Curt 56267 wire harness in my Murano. Easy installation - followed video but still have problems. The trailer only lights on left side with running lights, brake lights work on both sides but blinkers dont work. Ive double checked the ground and even moved it to an existing bolt. Ive tried everything - even ordered a Tekonsha confirmed fit to make sure the Curt harness wasnt bad. Same issue. A local trailer repair place told me it may need a tow package relay as some Nissans have an issue. The local Nissan dealer doesnt show the part exists for a Murano. Help!!

asked by: Mike C

Expert Reply:

You will not need to install any relays on your 2016 Nissan Murano for the Curt T-Connector # C56267 or the Tekonsha T-One # 118660 to activate the lights on your trailer.

It sounds like you have an issue with the wiring on your trailer, not your Murano. You can confirm this by using a Circuit Tester, like part # PTW2993, to test the 4-Pole connector on your Murano and using a 12V power source, like your Murano's battery, to test the 4-Pole connector on your trailer side. You can also check the connector on both your Murano and your trailer to make sure that there is no corrosion or loose wires.

Have a helper sit in the Murano and activate the various lighting functions while you test the 4-Pole with the circuit tester. If the circuit tester shows that all of the pins are sending the proper signal then the problem is definitely on your trailer side.

To test the 4-Pole on your connector just use the 12V power source to activate each lighting function on your trailer. If the lights don't work when you are doing this test then you will want to check the wiring on your trailer. Check all of the grounds (the lights usually have grounds too) and make sure that they are securely connected to a clean, bare metal surface. Sometimes even some paint can cause issues. Check the wiring for any places that look bent, damaged, corroded, or have exposed wiring. You can use 16 Gauge Wire # 16-1-1 and Butt Connectors # DW05744-5 to replace any wiring that needs it.

If the connector on both your Murano and your trailer are working correctly and the wiring on both look good then you will want to take your setup to your trailer shop and let them physically inspect it.

I have attached a helpful article on troubleshooting a 4- and 5-Way wiring setup that you can use as well.