Troubleshooting Curt T-Connector C56349 Not Working On 2018 Toyota Tacoma TSS

Updated 02/26/2025 | Published 02/24/2025

Question:

I have a 2018 Tacoma TSS without the tow package. I installed the actual hitch and have tried the Curt kit for this truck twice, and it did not work either time. The first one I chalked up to possibly being a bad kit, which happens sometimes. I installed the 2nd one the same way watched the video and neither one works at all. I have seen articles online about this particular model being unable to be wired up and have it work, unless it was pre-installed from the factory. I guess I have 2 questions. 1. Can you confirm that this should work, and 2. Is there anything I should do differently from what the video shows to install this and make it work? Thank you for your time.

asked by: Jason R

Expert Reply:

Hey Jason, thanks for reaching out. The Curt T-Connector # C56349 definitely should work on the 2018 Tacoma. It is for all models of Tacoma 2016-2023. We have done several Tacoma installs here and have not run into any issues.

When you say the Curt kit "didn't work", can you elaborate on that a bit? Were there no lights on the trailer at all? Or were you only getting certain lights to come on? Let me know because that will help us narrow down the correct troubleshooting steps. As long as you followed all of the steps in the instructions, it should be working. Bad converters are not unheard of, but getting two bad ones in a row is very improbable and is likely an indicator of an underlying issue.

A lot of times where we will start is by taking a multimeter and testing the converter module. Test the input wires and make sure the signal going in to the converter is normal. If input is normal, but there is no output signal, we can chalk it up to a bad converter. If the input signal is not normal, there is something going on on the vehicle side. Could be a blown fuse or shorted/damaged wiring. Let me know exactly what happened when you hooked up the wiring harness and we can take it from there. Just reply below and I will get back to you.

expert reply by: Jesse M

Jason R.

2/26/2025

Hello Jesse. Thank you for responding. It didnt work at all. I tried my utility trailer and my boat trailer. Both have fully functioning LED lights and neither worked with this kit. I tried both trailers with a different vehicle and the lighta worked perfectly. I followed the instructions that came with the kit, and the youtube video both times and neither kit worked. I checked the inline fuses on both kits and they were intact as well. Even put new ones I had in there juat to make sure. Other than checking the current in the wires, I am not sure what else to do. Again, thank you for responding Jesse.

Jesse M.

2/26/2025

@JasonR Of course! I am here to help. So we know the trailer lighting is good so we can cross that off the list of suspects. Testing the wires at the converter will definitely be the next step here. If you get around to it, come back here and let me know your findings. Also make sure your black wire is connected firmly to the battery, and make sure your ground is good. Ground to a bare metal surface with no paint or corrosion. Take a look at this article it should help:

Helpful Links

faq-4-5-way-troubleshooting.aspx

Jason R.

2/26/2025

@JesseM Thank you Jesse. I will definitely let you know how it goes.