Factory towing - wiring - RTH

[i4c4lo]

I am trying to plug a trailer harness (Hopkins Towing Solutions - Part Number #43910 to a 2013 LX570.

There is a factory plug in the rear next to the AHC reservoir (passenger rear) next to the spare tire. The plug from Hopkins does plug into the matching factory plugs that has a dummy plug to protect it.

I am not getting power to the trailer harness at all. I have checked all fuses related to towing (even swapped the 30A just in case).

My question is is this thing actually live from the factory OR do I need an actual brake controller to power this plugs? What have the people that tows with their 200/LX have done?

Thank you.

 

[Rigger]

Not sure if this will help but the PO of my 08 towed with it and had installed a brake controller in the truck.

 

[txtortoise]

Since the 4-pin adapter is used for trailers without electric brakes, I wouldn't think a controller is needed to complete the circuit. Do you have another trailer you can plug the truck to, either 4-pin or 7-pin. If you are using a voltmeter or other tester and just getting no power on any pins, it would seem to be a truck wiring fault somewhere, somewhat obviously.

 

[i4c4lo]

Rigger - thank you.

txtortoise - I did plug the trailer into a Tacoma truck and trailer lights worked fine. I also got a trailer plug tester also from Hopkins from a local O'reilleys. I plug this tester into the LX and nothing. I plug it into the Tacoma and it lights up. So I was hoping I didn't need a brake controller to make it work but it is looking like I might need to - I have one, I just didn't have time to open the dash area and wire it up. I will give an update in a few days once I do this and see what happens.

 

[Rigger]

I took the controller off of the 08 LC installed it in my 14 Tundra. It's plug & play. Easy peasy.

 

[chilibit]

The controller or the lack of a controller is not the underlying issue. Me thinks.

 

[Romer]

You shouldnt need a controller for the lights to work. If I recall there is a connector from the harness to the trailer controller. Check to make sure it is plugged in. Troubleshooting all the signals is very easy. My Australian Camper wasn't wired right when it arrived and I ihad to validate everything was wired right. Hope this helps

 

[i4c4lo]

Thank you guys - I am out of town right now and will check on it later this week and will give an update.

 

[LCHardriver_02]

I tow with my 2010 LX using the factory installed wiring harness. I agree that you should have power to the outlet for your lights regardless of the brake controller.

For me, I needed a brake controller since our trailer is fairly heavy. I purchased and installed a pre-manufactured harness to power my Tekonsha brake controller, which was very easy to install. If you do go with a brake controller, I would highly recommend both the controller and the associated wiring harness. Here is a link, just in case:
2010 Lexus LX 570 Brake Controller - Tekonsha

 

[OGBeno]

Thank you guys - I am out of town right now and will check on it later this week and will give an update.

s*** Amando..... You are rolling in a 200 these days? Did you get rid of the other rigs?

You really should bring that on the Rubithon this year.

That way you can be one of the few to drive a 100 and a 200 through the Rubicon with NorCal.

 

[i4c4lo]

Beno, yeah I got rid of my 100. It had been a GREAT rig. It was time for another. I had that car for 12 years.

Hahaha Rubicon .... I have access to the U-80 and that would more fun in the Rubicon than the LX. hahaha

Update on this - I did install a Tekonsha P3 using the factory harness behind the dash. Still didn't fix my problem - I needed to mount it anyway.

Looking at that diagram that Romer posted above (thank you). Here is my observation with the harness that I have from eTrailer - the Green and the Brown are swapped. The Yellow and the Red is also swapped.

I started a dialogue with eTrailer last Thursday and asked them to send me a new one but someone from their end cancelled the return. I am hoping to sort this out soon. I will post an update again. Thank you gentlemen.

 

[TeCKis300]

UPDATE: I ran into this exact problem with the damn Hopkins adaptor. Short story, it's wired completely WRONG. Only circuit that was correct was the right signal pin. They must have had a bad batch as I've seen a number of threads across the web with the same issue.

I spent 4 hrs debugging this problem, when picking up a new to me Airstream. Debugged the airstream, my new Prodigy P3 brake controller. In the end, isolated this down to the Hopkins adaptor. Resorted to cutting the hopkins harness and re-map each pin with wire nuts. Fortunately I had my voltmeter with me. Note that this also blew a 30amp "towing" fuse at the fuse box nearest the battery in the engine bay.

 

[TWillz]

I think i must have one of the bad Hopkins adapters too. I only have power to one trailer light, and have been trying to figure out what was causing this. I didn't even realize my used '09 didn't have the factory trailer harness until I had driven it all the way back home to IL from the dealer in Iowa where I bought it. Installed a Hopkins last year so I could tow the boat, and have been checking fuses and wires since February trying to get all my trailer lights working. I guess I'll swap that out and see if it solves the problem.