Troubleshooting Trailer Wiring Harness On 2005 Volvo XC90

Updated 07/02/2015 | Published 07/01/2015

Products Featured in This Question

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(157)

$55.94

Hook Probe Circuit Tester

(62)

$13.33

Question:

I have a 2005 volvo xc90. When I hook up a trailer to my xc90 I only have the passenger side light come on but no brake light or turn signal. The drivers side does not light up at all. I have tried different trailers as well and still have this problem. I have checked the fuses and they look ok and all the lights work on my car. Is it possible that the converter thing has gone bad? I dont want to buy a new one yet if that will not fix the problem. Is there a way to troubleshoot this? Thanks

asked by: Jeffrey

Helpful Expert Reply:

You can do some testing to find the source of the problem. I recommend using a circuit tester like part # PTW2993 and have someone run through the functions while you test the pins on the vehicle side connector at the rear of your XC90. If you have a plug-in harness the problem could be a set of connectors that are not fully seated. You may have an inline fuse that is blown, or a relay is bad. You also want to make sure the harness is grounded to a clean, bare metal surface.

If you are not showing current at the connector on the vehicle you can check the wiring that is leading to the converter. If you are getting power to the converter, then chances are the converter has gone bad and will need to be replaced. The wire harness I recommend for your vehicle is the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector, part # 118411.

expert reply by: Jeffrey L