(New guy) - 2013 Tahoe LT - Tekonsha P3??

[wsteele]

Bad news. The wiring harness you need likely isn’t curled up behind that black cover. At least, it doesn’t come from the connector/circuit breaker panel underneath. The harness you need is a four wire harness that breaks out of a larger bundle running just underneath the dash panels. It should have a label hanging from it with a bar code and some nomenclature of what each color wire does (at least mine does). Those 4 wires will be butt spliced to the four wires coming from your P3.

If your truck has the pre-wired towing package, those 4 wires should be right there. I misread the wiring bundles and thought mine came from that box, sorry for the confusion.

 

[gooffeyguy]

That black box is the upfitter distribution box and the brake controller wires DON'T come from there.

My cover looks the same, but has a hole in the center where a 2" long christmas tree style body panel pin goes and secures it in place

 

[BooBoo]

Thank you again! I've been out there this morning being more thorough in my investigation and will post the final results before too long to (hopefully) save another 2013 owner some trouble.

 

[wsteele]

Thank you again! I've been out there this morning being more thorough in my investigation and will post the final results before too long to (hopefully) save another 2013 owner some trouble.

Good luck.

It is too bad as on later models, that panel the cover shields has a socket for the trailer brake controller wiring and Tekonsha actually sells a harness that goes right from the P3 to that panel. Good luck finding the 4 wire bundle under there.

 

[gooffeyguy]

Yeah, my 2001 has a socket down in that area that the brake controller wire harness plugs into. The 07-14 model years don't.

The brake controller wiring on my 2012 was way up under the dash and took me a while to find. It is a lot easier if you remove the knee bolster panel that runs horizontally under the steering wheel. It's 2 bolts/screws along the bottom and the top just has clips and pops off

 

[BooBoo]

Mystery solved! Actually, this was probably more a matter of me being challenged by unchallenging things, but I thought that I would post a couple pictures in the hope of saving another 2013 owner some hassles. (It seems like 2013 is the difficult year for some reason, I could find the plug-in harness for the P3 for years earlier and later.)

FIRST, the wiring junction box cover doesn't need to come off. Which is good, because that body pin retainer is in there so strongly that I just didn't want to risk increased force to remove it and possibly damage the wiring block that it's protecting.

I found the trailer wire bundle WAY up in the wiring and completely taped up. The label shown in the picture wasn't easily visible, but I realized that it was the giveaway on what might be in there.



The installation video at eTrailer covers this, (the 2011 video shows the separate wires - the later model video uses the adapter plug),
but I thought that for myself and others it might be helpful to "be sure" of what is what.

I used my wife's small scissors to remove the tape. She wasn't home and probably won't read this.

As noted, the red wire on the FENDER side is controller power and goes to the SILVER post.

The red wire sort of under the brake reservoir is apparently ground, as the video says to attach it to the BLACK post.

POST NUTS:

I don't have existing nuts on those posts, so will need to get some. According to eTrailer, they are:

M6 x 1.0
&
M8 x 1.25



I hope that this helps somebody. Thanks to everybody who helped ME!!

 

[Joseph Garcia]

Thank you for posting your results.

 

[gooffeyguy]

Mystery solved! Actually, this was probably more a matter of me being challenged by unchallenging things, but I thought that I would post a couple pictures in the hope of saving another 2013 owner some hassles. (It seems like 2013 is the difficult year for some reason, I could find the plug-in harness for the P3 for years earlier and later.)

FIRST, the wiring junction box cover doesn't need to come off. Which is good, because that body pin retainer is in there so strongly that I just didn't want to risk increased force to remove it and possibly damage the wiring block that it's protecting.

I found the trailer wire bundle WAY up in the wiring and completely taped up. The label shown in the picture wasn't easily visible, but I realized that it was the giveaway on what might be in there.

View attachment 305111

The installation video at eTrailer covers this, (the 2011 video shows the separate wires - the later model video uses the adapter plug),
but I thought that for myself and others it might be helpful to "be sure" of what is what.

I used my wife's small scissors to remove the tape. She wasn't home and probably won't read this.

As noted, the red wire on the FENDER side is controller power and goes to the SILVER post.

The red wire sort of under the brake reservoir is apparently ground, as the video says to attach it to the BLACK post.

POST NUTS:

I don't have existing nuts on those posts, so will need to get some. According to eTrailer, they are:

M6 x 1.0
&
M8 x 1.25

View attachment 305112

I hope that this helps somebody. Thanks to everybody who helped ME!!

My wires were way up there and hard to find also.

Both posts on the front of the power distribution box are hot (+) and one goes to the 12v power in the 7 pin trailer connector plug on the receiver hitch. Some trailers will use that to charge batteries or power lights/electrical equipment.

 

[BooBoo]

My wires were way up there and hard to find also.

Both posts on the front of the power distribution box are hot (+) and one goes to the 12v power in the 7 pin trailer connector plug on the receiver hitch. Some trailers will use that to charge batteries or power lights/electrical equipment.

Ah, thank you for clarifying!

 

[Fless]

If the 12v aux powering is always hot (which it is on my NBS) then be careful about leaving the trailer connected electrically while making longer stops for things like lunch, etc. It can drain your battery if you're powering something that takes a lot of current, like a fridge. And be sure to plug it back in before you take off again; I got in the habit of checking a few trailer lights after each long stop.