[Zonyl]

I've been following your posts. I was hoping you would be the guinea pig and take on the wiring. I didn't yet because I knew it would be a pain.

My new hitch is basically for the bike rack, but I do have a Harbor Freight small trailer with 8" wheels and old 12 Volt 1157 tail lights. There is the issue.

On the '23 Niro, the power for the LED tail lights comes from multiple sources. And I don't think it is even 12 volts. And the power for the turn signals is a whole different matter. Now, you have to find the power for the running lights.

I think before I even attempt to try trailer wiring, I need to update the trailer lights on my trailer from old 1157 bulbs to new LED tail lights. Maybe some cheap ones from Harbor Freight ?

That power for the tail lights is on a CAN bus. It's coming from some module somewhere. It'll take some searching to determine the sources.

As little as I ever used the Harbor Freight trailer, I was just going to risk it and not have any trailer lights.

If you figure it out......... post back.

From what I can tell in the schematic from the service manual, it is 12v at the light connector harness but very low driving current. A powered universal trailer converter should work and one arrives today. I'll definitely post back when it is all done.

 

[TheAirman]

Yes. It'll be interesting to know.

I saw a Tesla Model 3 pulling a cheap little trailer the other day, and I didn't notice if their trailer lights were working or not. But I imagine they were facing the same issue. Where to get 12V for the trailer lights with LED tail lights that aren't 12 Volts.

The Niro tail light plug is easy access under that panel in the trunk. I just haven't had the time to put a multi meter on it.

 

[Zonyl]

Yes. It'll be interesting to know.

I saw a Tesla Model 3 pulling a cheap little trailer the other day, and I didn't notice if their trailer lights were working or not. But I imagine they were facing the same issue. Where to get 12V for the trailer lights with LED tail lights that aren't 12 Volts.

The Niro tail light plug is easy access under that panel in the trunk. I just haven't had the time to put a multi meter on it.

Mystery solved, as indicated in service manual and measured, It's 12V for sure. It could be driven by CAN bus further up the chain (actually doubt it is that sophisticated as I didn't get a bulb out indication upon disconnect), but at this point it is good ol 12V.

The unfortunate bit is the turn signal harness is buried under the rear bumper. Honestly though missing turn signals isn't critical and probably won't bother with it. At best I'll get that cheap rf bike turn signal thing https://a.co/d/bdq4Lht and harvest the remote and wire up the signal lines to it's led output. I really don't want to tear apart the bumper

 

[sighttomtom]

Yes. It'll be interesting to know.

I saw a Tesla Model 3 pulling a cheap little trailer the other day, and I didn't notice if their trailer lights were working or not. But I imagine they were facing the same issue. Where to get 12V for the trailer lights with LED tail lights that aren't 12 Volts.

The Niro tail light plug is easy access under that panel in the trunk. I just haven't had the time to put a multi meter on it.

12 volt accessory battery provides power to everything "accessory" in all vehicles including full EV. from Curtis website the 2019[mine] and 2023[yours] has the same connector. if this is true, it's straight forward installation. power source is your accessory battery which has full power even when the ignition is in off state. only pain point is removal of the lot of plastic panels and bolts that hold them. I ran mine inside the vehicle unlike Curtis example of running the cable outside/underbody. I think full EV has accessory battery located in the back of the vehicle? if this is true for Gen2, you should be able to wire this up in few minutes.

 

[sighttomtom]

Mystery solved, as indicated in service manual and measured, It's 12V for sure. It is likely driven by CAN bus further up the chain, but at this point it is good ol 12V.

The unfortunate bit is the turn signal harness is buried under the rear bumper. Honestly though missing turn signals isn't critical and probably won't bother with it. At best I'll get that cheap rf bike turn signal thing and harvest the remote and wire up the signal lines to it's led output. I really don't want to tear apart the bumper

you don't want to use just any power source as it can overload on the source. Power should be connected directly to the battery with provided fused line [heavy duty] to ensure it can safely accommodate power needed for the trailer even if it's just a simple parking/brake lights.

 

[Zonyl]

12 volt accessory battery provides power to everything "accessory" in all vehicles including full EV. from Curtis website the 2019[mine] and 2023[yours] has the same connector. if this is true, it's straight forward installation. power source is your accessory battery which has full power even when the ignition is in off state. only pain point is removal of the lot of plastic panels and bolts that hold them. I ran mine inside the vehicle unlike Curtis example of running the cable outside/underbody. I think full EV has accessory battery located in the back of the vehicle? if this is true for Gen2, you should be able to wire this up in few minutes.

Curtis is wrong and I just had a long conversation with them about it last week. Finally got them to admit and return the product they offered. Had to send them photos and copies of the service manual before they stubbornly admitted to it. They do not offer any plug and play converter at this time (because they literally didn't realize it until now). Even the 23 service manual from Kia still refers to the upper tail lights as "combination lights" when they aren't anymore. The turn signal is now a separate housing and location (poor technical writing)

The 23 Niro has completely different connectors and harnesses. The EV and PHEV (hev?) models of the 23 have the 12v battery in the back as shown in my picture above. Getting 12V, running lights, and brake will be super easy (less than 5 minutes with wire taps). Getting to the turn signal harness is likely a 1-2 hour project and not one I care to bother with. Those turn signals are probably the worst possible design I have ever seen as you need to remove the wheel and a bunch of body panels just to change the bulb

 

[Zonyl]

you don't want to use just any power source as it can overload on the source. Power should be connected directly to the battery with provided fused line [heavy duty] to ensure it can safely accommodate power needed for the trailer even if it's just a simple parking/brake lights.

Yes, as I mentioned earlier, you will likely need a "powered" (12V separate line) converter. However given what I am seeing with my meter and lack of bulb out detection that is likely unnecessary. I got a powered one anyway (safe than sorry) because the battery is literally inches away from the upper tail light harness.

The turn signals may be a completely different story though, but really don't care about them for now.

It all arrives today and will definitely document everything tonight or tomorrow.

 

[Zonyl]

Went exactly as expected and no issues using the curt universal powered trailer wiring adapter. Running lights and brake are working.

No turn signals yet, but I'm working on that.

 

[TheAirman]

Excellent technical detective work !!!!!!!!! You even do your work on a granite table. Wow !!

First:
The EV has no 12V battery in the back. Mine is in the front under the frunk. So a powered and fused trailer light converter is out for me.

2) In your picture, is that the connector for the rear tail lights you picked up the 12V ? It might be 12V but I wonder if it carries the amps required to light another pair of lights.

3) In your picture of the lights working, are you using a powered converter hooked to your 12V battery, or did you just tap the rear tail lights wires?

Your little trailer is nice. But it already has LED lights. I need to upgrade mine to LED because I think the '23 Niro is not sending enough amps back to those "combination" lights like in the old days.

That 12V you found is more of a control voltage and it is not coming from a plunger switch at the brake pedal like the old days either. On the EV, my brake lights automatically come on with adaptive cruise, iPedal, and different levels of Regen one pedal driving.

I wasn't planning on using those turn signals either, but how I'm going to get lights to work is still a work in progress.

 

[Zonyl]

Excellent technical detective work !!!!!!!!! You even do your work on a granite table. Wow !!

First:
The EV has no 12V battery in the back. Mine is in the front under the frunk. So a powered and fused trailer light converter is out for me.

2) In your picture, is that the connector for the rear tail lights you picked up the 12V ? It might be 12V but I wonder if it carries the amps required to light another pair of lights.

3) In your picture of the lights working, are you using a powered converter hooked to your 12V battery, or did you just tap the rear tail lights wires?

Your little trailer is nice. But it already has LED lights. I need to upgrade mine to LED because I think the '23 Niro is not sending enough amps back to those "combination" lights like in the old days.

That 12V you found is more of a control voltage and it is not coming from a plunger switch at the brake pedal like the old days either. On the EV, my brake lights automatically come on with adaptive cruise, iPedal, and different levels of Regen one pedal driving.

I wasn't planning on using those turn signals either, but how I'm going to get lights to work is still a work in progress.

The easy upper tail light connector: Pin 1 is 12V lights, pin 2 is 12V brake, and pin 3 is ground

1.) Ah. Interesting. I'll check the schematic. you might be able to pick up 12V from the lift gate.

2. &3) the schematic shows it is connected to an IPC module so you are correct that it isn't an old school brake pedal switch. However, it definitely isn't CAN at the harness and given the number of LEDs in the upper lights, I think you have quite a bit of current to work with. All that said, I did use a powered converter as the battery was right there for me. In the schematic it shows a " bulb" connection for those so it may be high current enough.

However, the lower turn signals harness schematic shows all sorts of things; bulb, led, reverse, telltale signal and there may be more line level stuff there.

 

[MFKiaNiro]

I bought the just released Curt hitch # 13531. It is made to fit all the 2023 Niro line, including the HEV, PHEV and EV.

On the HEV and PHEV, you have to lower and support the rear of the exhaust pipe and lower and support that vapor canister. On the EV, I only had to remove the rear under body panel.

I bought it from etrailer, and of course when they ship from etrailer, they just throw it in a box unprotected, and when it arrives after the UPS people toss it around, it was all scratched up and half hanging out of the box. If you buy from etrailer, be prepared to get on the phone when it arrives damaged.

It will fit, but I had some slight problems with my install. Mine missed fitting perfectly by about .25". But it did finally fit and tighten down.

I called Curt and told them they were off by 1/4". They claimed it was someone else and my hitch was flexed.

I think it was either UPS, or etrailer just tossing a heavy metal item in a box.

Here is a picture using an inspection mirror showing the bolt at the rear drivers side. With the mirror you can see the front and back of the bolt contact with the hitch. (the silver is rust preventative. The gold bolt is the mounting bolt.):

View attachment 8266

Here is the bracket that contacts the bolt in my install. It is circled and with an arrow.

hitch.pdf

Here is what Curt sent me telling me how to fix my "flexed" hitch:


View attachment 8268

It did fit, but if that bracket was just a little bit lower or smaller, it would have fit right up. Maybe your experience might be different.

I have a 2023 Phev. Curt and E Trailer both told me it was the C77NR that was made for the Phev. I can't even find the 13531 on the E Trailer site. I had a 2018 Niro Phev and installed a Curt unit on that one and it wasn't too complicated (some grinding of the hitch mount and trimming of some plastic). So I am somewhat familiar with the installation. I just want to make sure I get the proper unit for the Phev.
Could you double check your order number?
Thanks!

 

[Zonyl]

I have a 2023 Phev. Curt and E Trailer both told me it was the C77NR that was made for the Phev. I can't even find the 13531 on the E Trailer site. I had a 2018 Niro Phev and installed a Curt unit on that one and it wasn't too complicated (some grinding of the hitch mount and trimming of some plastic). So I am somewhat familiar with the installation. I just want to make sure I get the proper unit for the Phev.
Could you double check your order number?
Thanks!

I installed the c77nr on my PHEV. See the other thread for details on installing

 

[MFKiaNiro]

Great! Thanks! Do you remember what basic wrench sizes you used? Standard? Metric?
Thanks again

 

[Zonyl]

Great! Thanks! Do you remember what basic wrench sizes you used? Standard? Metric?
Thanks again

Hehe. My toolbox socket drawer is a mess and just brought the bolt to it and matched it without looking at the size. If I get underneath again I'll have a look-see.

 

[TheAirman]

I have a 2023 Phev. Curt and E Trailer both told me it was the C77NR that was made for the Phev. I can't even find the 13531 on the E Trailer site. I had a 2018 Niro Phev and installed a Curt unit on that one and it wasn't too complicated (some grinding of the hitch mount and trimming of some plastic). So I am somewhat familiar with the installation. I just want to make sure I get the proper unit for the Phev.
Could you double check your order number?
Thanks!

Sorry for the late reply.
The c77nr is E trailers stock number for the #13531.

Class 3 Trailer Hitch, 2" Receiver, Select Kia Niro, EV

You don't need to buy from E trailer. Other places sell the 13531 Curt hitch. Just make sure it's a Curt 13531 no matter what the retailer stock number is, becuse it will fit the PHEV. You need to lower the exhaust and canister.

 

[TheAirman]

Hehe. My toolbox socket drawer is a mess and just brought the bolt to it and matched it without looking at the size. If I get underneath again I'll have a look-see.

They are metric bolts. Sometimes on these bigger, meaty metric bolts you can find a SAE size that is close. Just use caution not to strip it and bust a knuckle.

Also, many thanks for the pin out of the brake light plug.