Troubleshooting Turn Signals After Installation of Curt 4-Pole Wiring Harness C56251 in Kia Sportage

Updated 07/31/2017 | Published 07/28/2017

Question:

I installed a custom wiring harness part number 56251 on my 2012 kia Sportage. And the upper rear turn signals are not working. Please send me a wiring diagram thank you

asked by: Ivan N

Helpful Expert Reply:

Thank you for your wiring harness purchase.

The Curt 4-pole wiring harness kit # C56251 is a custom-fit product confirmed to fit your 2012 Kia Sportage. Since this installs using connectors that match those on the car there really is no wiring diagram per se, but the instructions are linked for you. Only the one power wire to the battery requires a spliced connection; this goes to the positive terminal via the included fuse holder.

You do not mention whether it is the vehicle or trailer turn signals that do not work. If the car's own turn lights do not work after you installed the harness then unplug it and inspect the metal contacts on both the harness and vehicle connectors. Something as simple as a bent pin (that does not make proper contact) could cause an issue on either the vehicle or trailer. Trapped foreign material or corrosion - even slight greenish discoloration - can indicate a corrosion issue that could interfere with a signal transmission. Try re-connecting the taillight wiring without the Curt harness.

If it is the trailer lights that do not work inspect the two 4-pole connectors, vehicle and trailer, for signs or corrosion. You can also check the trailer turn lights for a loose ground wire or bad bulbs. It is easy to test the trailer on its own by using the vehicle battery or a spare directly connected to the 4-pole trailer connector. If the lights on the trailer work when it receives power direct from a battery then you know the issue is on the vehicle side.

Please tell me more about the issue and I will be glad to assist further. You can also refer to the linked articles on troubleshooting trailer wiring.

expert reply by: Adam R