It is simply a regular 1 1/4 inch hitch, nothing special about it. The only problem I have when towing the trailer is my lighting. It blows a fuse if i turn all of the lights on. It is fine for brake and signal lights though. I therefore only use it during the day. The trailer company that installed the hitch and wiring called our local Kia and were told that the trailer lights are too much of a draw on the electrical system and he hence blow the fuse.
Using a new trailer plug, direct all the hot wires (Brown, Green and Yellow) to a set of relays mounted on the trailer. This will be your control circuit with one relay for each of the hot wires, it will plug in to the existing plug that you already have on the car.
Now you need to build a power circuit. Install a new HOT wire of sufficient gauge to handle all of the trailer lights on the car, where and how are up to you, but make sure you use a fuse on the wire, as close as possible to your chosen power source. Terminate this near your existing trailer plug with a flat four connector (I am assuming your trailer is using a flat four) where you wire your new HOT wire to Brown, Green, and Yellow.
Finally, on your trailer, take the brown wire from the existing trailer wiring harness, cut it and attach the ends to the LOAD terminals on your Brown relay. Do the same for Yellow and Green.
Now, when you step on the brakes, use signals or lights, you are not powering them through your existing trailer hookup, you are only powering the relays. All the power for your lights is going through your new harness, with on/off being controlled by the relays closing/opening.
You could also do all of this on the car side of things, just not sure how they wired in your trailer pigtail. Principle is still the same, use the signals from the harness for the control circuit of relays and let the relays pass full juice to the pigtail.
OR, now with the advent of LEDs, convert all your trailer lights to LEDs and the car should be able to handle the draw.
Last edited by 19_Opt_SX; 03-23-2019 at 09:53 PM.
There is a 2" hitch made for the Optima, it's the EcoHitch from Torquelift. I have one but have not installed it yet due to time constraints. I probably will this week due to hefting my fatbike onto my roof rack being such a pain with having the kayak racks up there already.
As to voiding the warranty, that is a load of bull. It is clearly marked as a Class 1 only and would only void the warranty if you overloaded it, which they would have to show you did, probably through metal deformation. That you 'could' is not a valid argument since you 'could' with any hitch, regardless of size. I plan on only having bikes on mine, however.