How To Get Camper Lights Working Using Tow Ready Adapter # 30717 on 2005 Volvo XC90 With 4-Way

Question:

I have a 2005 Volvo XC90 towing a 2009 Coleman Westlake pop up with a 7 pole harness. I installed your 4 pole harness to my volvo and then attached the 4 pole to 7 pole adapter as my camper is 7 pole but m other trailers are 4 pole. None of my camper lights are working. Can I plug the black power cable to the campers battery instead of running it to the cars battery? Are there any other wires that NEED to be attached for the lights to work besides power and ground?

asked by: Dan

Expert Reply:

First, on the # 118411 wiring harness you installed on your 2005 Volvo XC90 check the 4-Way connector with a circuit tester like, like part # PTW2993, to make sure the 4-Way is working correctly. If it is not, check to make sure you have the white wire from the wiring harness attached to a good ground and the yellow power wire from the converter box installed to the fuse box on your vehicle correctly with a good fuse installed in the fuse holder. I am including a link to a video that will show those wiring harness connections being made on the 2007 Volvo XC90.

The Tow Ready 4 Pole to 7 Pole Adapter, part # 30717, you have referenced, is designed to be installed on the tow vehicle with the 12-volt black power wire going to the vehicles battery and the white wire for ground. It will only give you a 7-Way connector on the vehicle. The other wires, blue and yellow, are for brake controller output (blue) and auxiliary wire (yellow) for reverse light or reverse lockout on trailer brakes. These wires do not need to be connected for the lights to work.

If you are trying to plug in the # 30717 adapter to the 7-Way on the camper and connect the black power wire to the trailer battery it will not work because the 7-Way on your camper now is already connected to the trailer battery and when you try to connect the power wire from the adapter to the trailer battery it will cause it to short out.

Since you are needing to have both a 4-Way connector and a 7-Way connector available for towing I would recommend to look at the Hopkins Adapter, part # 37185. This adapter will install on your Volvo and give you both a plug-in for a 4-Way and a 7-Way connector to tow your camper with the 7-Way and any other trailers with a 4-Way.

The wires you will need connected when using the # 37185 adapter to just give you lights on the camper would be the black power wire to the vehicles battery with an inline 40 amp breaker (# 9510) and the white ground wire. The blue wire is for a brake controller and the purple wire is for reverse lights or reverse lockout on trailer brakes.

If you are needing to connect a brake controller to your vehicle I would recommend to use the # ETBC7 installation kit. This kit will come with all of the hardware needed to make the other wire connections on the 7-Way when connecting a brake controller to your vehicle. I am including a link to a video of how to install the # ETBC7 on your vehicle.