2018 wiring harness for brake controller

We traded in our 16 and now have an 18. For the 16 we purchased a harness that was just plug and play. Plug one end in to truck and the other end in to the brake controller. We couldn't find the end of the harness under the dash. Took it to the dealership and at first they couldn't find it, but then eventually found it. Now they are telling us that the plug on the harness has changed for 2018 and the adapter we have will not work. Can anyone confirm that the plug from the 16 and the plug on the 18 are different or not?

 

All of my other new Trucks and SUV's (Toyota & Ford) have come with a wiring harness with open wire ends to splice into whatever controller wiring you need. My 2018 is the first one to not come with a harness. A couple websites sell the harnesses and claim that they will fit 2016-2018, but I don't know if they are being truthful.

https://www.tacomaworld.com/threads/2018-wiring-harness-for-brake-controller.528103/

 

Tekonsha lists part #3017-p for 2016-2017 Tacomas and part #3031-p for 2016-2018. Looks like the only difference is the 2018 model added a separate ground wire on the truck side of the plug. Wonder why?

https://www.etrailer.com/Accessories-and-Parts/Tekonsha/3017-P.html

https://www.etrailer.com/Accessories-and-Parts/Tekonsha/3031-P.html

 

Interesting...Since I just ordered a new brake controller and harness from etrailer this morning, and the CSR said the 3017-P was the correct one for my 2018. I guess we'll find out this weekend!

 

Yeah the plug on the truck side looks exactly the same. Let us know if it works!

 

Haha...the response from etrailer on why there are two parts:

"Technically they both fit! The difference is that the # 3031-P is replacing the # 3017-P as it was designed with an extra ground wire which allows the harness to function better."

So...um...why wouldn't you recommend the part that allows the harness to function better? Why would the old part even be linked to the truck anymore?

 

New member here - I just got a 2009 that has the towing package. Owners manual says the brake controller connector is under dash by the hood release - but I haven't been able to find it. Will try again on my back with flashlite - but meantime - does this location match up what others have found??

 

Yes, that general location matches the many other Toyota’s I’ve owned. It is back in the corner. Follow the e-brake up, and it’s hiding up behind it. In fact, it’s easier to get to if the e-brake is disengaged.

 

I recently bought a Tekonsha P3 and the 3017-P harness. About a week after it was installed, the ground wire on the truck side of the harness melted and eventually led to a $5000 repair that Horizon Global (owner of Tekonsha) covered for me. They sent me their new harness with extra ground wire, which I have not plugged in and tried yet for fear of the part messing up my truck again. That said, be careful about installing the 3017-p in your truck! Tekonsha said they found a short in the P3, but I have yet to be convinced that solves the problem. I have the 2017 TRD sport with the towing package. Anyone else have this happen to them?

 

Thanks for the info. I am going to return the 3017-P and get the

$17 3031-P Tekonsha Trailer Brake Controller Harness, Compatible with Select Toyota Tacoma, Tundra

3031-P with the extra ground. Better safe than sorry! I haven’t heard of your issue happening to anybody else, and the Tekonsha P3 is what I had in my 4Runner for the last couple years. I’m sorry for your bad luck!

 

No worries, Smcbundy. I hope it goes well for you! I t was a shocker to me, since Tekonsha and Toyota are both so reputable. Still have not gotten a real answer from either of them...

 

Thanks for the heads up, I was about to install a 3017-P. I am also ordering the

$17 3031-P Tekonsha Trailer Brake Controller Harness, Compatible with Select Toyota Tacoma, Tundra

3031-P to be safe.

 

And this is why this forum is AWESOME!! I am needing exactly this. Thanks guys.