Aftermarket trailer brake ( tough question )

[twoplustwo]

Hi Folks,
I have a 2018 Chev LTZ ( without the factory trailer brake controller).
I checked the vin and can confirm 
I have the Z82 ( trailer package ) 
but do not have the JL1 ( trailer brake controller ) 
so it should be easy to install an aftermarket trail brake controller right...

Well.
I looked at a number of you tube videos and it should be plug and play.
There is supposed to be a standard 4 pin plug that I can wire up my controller and 
I found where it should plug in...( under dash by brake pedal ) 

but there is already something plugged into the slot.
There is however a pigtail coming out from it from it with different plug...

Dealership also confirmed that the trailerbrake controller slot should be empty

What Gives
Any ideas
 

[newdude]

Looks like someone had one in there already, and possibly used the GM/Curt one that comes with that adapter that you see installed there.  You should be able to plug your controller into the black end of that jumper harness that's sticking out.  

 

Trailer Brake Controller Harness SKU #51451 for $12.39 by CURT Manufacturing (curtmfg.com)

 

[twoplustwo]

One more thing I wanted to add,

I am the original owner - so there has been no modifications to the wiring in the truck.

Could this be a mistake from the factory - and they sort of included the wiring for the JL1 brake controller?

The  curt brake controller  shown is something I had from another vehicle  

 

[jscottl]

Looks like they plugged in your pigtail in maybe during dealer prep. It's usually just in the glovebox. My '11 and '17 trucks had connector just laying in glovebox and I bought both used.

Edited November 22, 2021 by jscottl

[newdude]

2 hours ago, jscottl said:

Looks like they plugged in your pigtail in maybe during dealer prep. It's usually just in the glovebox. My '11 and '17 trucks had connector just laying in glovebox and I bought both used.

 

 

The harness that comes in the glovebox has 4 blunt ends on it, not an actual connector on the controller side.  

[newdude]

2 hours ago, twoplustwo said:

One more thing I wanted to add,

I am the original owner - so there has been no modifications to the wiring in the truck.

Could this be a mistake from the factory - and they sort of included the wiring for the JL1 brake controller?

The  curt brake controller  shown is something I had from another vehicle  

 

 

 

That is not wiring for the factory JL1 integrated controller.

 

That harness that is in there isn't the factory controller harness either.  It only has the end that plugs into the junction box.  This is what the one in the glovebox would have looked like.

 

 

 

  

[MikeBMW]

1 hour ago, newdude said:

 

 

That is not wiring for the factory JL1 integrated controller.

 

That harness that is in there isn't the factory controller harness either.  It only has the end that plugs into the junction box.  This is what the one in the glovebox would have looked like.

 

 

 

  

Yep, exactly what mine looks like.
I had the dealer install a curt trailer brake and I still have that harness.

[Ravenkeeper]

On 11/22/2021 at 2:48 PM, newdude said:

 

 

That is not wiring for the factory JL1 integrated controller.

 

That harness that is in there isn't the factory controller harness either.  It only has the end that plugs into the junction box.  This is what the one in the glovebox would have looked like.

 

 

 

  

My truck came with this harness, but my truck also has factory trailer brake installed.

[dieselfan1]

Throw that harness away and get a Tekonsha brake controller with the plug and play harness. 

https://www.amazon.com/Tekonsha-90160-Primus-Electronic-Control/dp/B001P11SCM/ref=asc_df_B001P11SCM/?tag=hyprod-20&linkCode=df0&hvadid=198074801421&hvpos=&hvnetw=g&hvrand=17341988148998302457&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9019635&hvtargid=pla-383460128049&psc=

 

 

https://www.amazon.com/Tekonsha-3016-P-Control-Wiring-Adapter/dp/B00GJX1NYE/ref=mp_s_a_1_3?crid=2EYF91AYJKRQ3&keywords=tekonsha+brake+controller+harness+2018+Silverado&qid=1637761937&qsid=145-2565671-4071844&replacementKeywords=tekonsha+brake+controller+harness&sprefix=tekonsha+brake+controller+harness+2018+silverado+%2Caps%2C155&sr=8-3&sres=B00GJX1NYE%2CB00GSWBCEM%2CB00H2WJ4OW%2CB00QRWQV0I%2CB010GLVW90%2CB00S0HFMNU%2CB099MRFNG8%2CB00L0Y6KMW%2CB0009FB7DA%2CB06XH6PD2X%2CB001EOV474%2CB08ZMZ3Z2Y%2CB00K2GK2UK%2CB08CWPWV1L&vehicle=2018-47-491------------&vehicleName=2018+Chevrolet+Silverado+1500