Go Back  MBWorld.org Forums > Mercedes-Benz SUVs, Trucks, Vans, Diesels, Other > GL Class (X166)
Help with installing a wired brake controller! >

Help with installing a wired brake controller!

Notices
GL Class (X166) 2013-Present

Help with installing a wired brake controller!

 
Old 04-24-2016, 05:44 PM
  #1  
Newbie
Thread Starter
 
Join Date: Jun 2013
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
GL 450
Question Help with installing a wired brake controller!

I have a 2015 GL450 and we tow a travel trailer. We currently use a Tekonsha Pridigy RF to tow with as it is wireless.
I would prefer to have a wired brake controller but I can't figure out where to hook one up. I've spoken to numerous dealers and no one seems to have any information when it comes to brake controllers. No one can find a wiring harness for it.

Any help would be appreciated.
KristanToronto is offline  
Old 04-24-2016, 06:21 PM
  #2  
MBWorld Fanatic!
 
Join Date: Nov 2012
Posts: 4,941
Likes: 0
Received 574 Likes on 448 Posts
A gaggle of MB's
If you have factory installed hitch - then you will find the connector in one of two areas - cabin inside firewall - zip tied up near brake harness - or "sometimes" under driver's footwell carpet. Use a strong flashlight for the search - can be a little contortionist to find..
fabbrisd1 is online now  
Old 06-02-2016, 02:53 PM
  #3  
Junior Member
 
Join Date: Oct 2014
Location: Phoenix
Posts: 40
Received 0 Likes on 0 Posts
2015 GL350
Did you find the harness and install a controller? Any advice or issues that you can share. I'll be purchasing a boat soon to tow - I understand that MB and other EU vehicles have had issues with trailers with LED lights and wondering if that's still true with the 2015. Hope it worked out for you.
andedave is offline  
Old 06-02-2016, 05:32 PM
  #4  
MBWorld Fanatic!
 
Join Date: Nov 2012
Posts: 4,941
Likes: 0
Received 574 Likes on 448 Posts
A gaggle of MB's
I have found 2015 GL's with factory installed trailer hitch to be more "tolerant" on LED trailer lights - however if on hookup you have a issue - then Towready makes a adapter with built-in resistor that many of my customers have used with no problem

Amazon.com: Tow Ready 20141 7-Way Flat Pin to 5-Flat Adapter with LED Lamp Out Bypass: Automotive Amazon.com: Tow Ready 20141 7-Way Flat Pin to 5-Flat Adapter with LED Lamp Out Bypass: Automotive
fabbrisd1 is online now  
Old 02-03-2017, 12:19 AM
  #5  
Newbie
 
Join Date: Feb 2017
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
2013 GL450
Reviving this thread to see if anyone can help me find the wiring harness for the brake controller. We have the tow package on our model. I just looked under the driver's side dash and can't even see where I'd need to start in order to get to the wires behind the plastic. Anyone able to help?
Wilde is offline  
Old 02-03-2017, 06:55 PM
  #6  
MBWorld Fanatic!
 
Join Date: Nov 2012
Posts: 4,941
Likes: 0
Received 574 Likes on 448 Posts
A gaggle of MB's
You will need strong flashlight + and be limber on-your-back contortionist

You are looking for a green-plug/socket - which will be attached to about a 10"-12" wire lead - and that lead/plug will be zip-tied or wrapped to other harness wiring.

Easiest to try to spot the green-plug - cut adjacent zip ties or wire wrap tape with a diagonal clipper - frees up the 10"-12" wrapped up lead.

1) Can be up/under driver's side dash in same wiring area as the hood-release/OBD port

2) Can be up/under dash - on the cabin firewall - in the upper area behind the upper brake pedal mechanism

Good luck !
fabbrisd1 is online now  
Old 02-04-2017, 07:31 AM
  #7  
skw
Super Member
 
skw's Avatar
 
Join Date: Aug 2012
Location: Boston area
Posts: 571
Received 31 Likes on 28 Posts
2019 GLS450
Originally Posted by fabbrisd1 View Post
You will need strong flashlight + and be limber on-your-back contortionist

You are looking for a green-plug/socket - which will be attached to about a 10"-12" wire lead - and that lead/plug will be zip-tied or wrapped to other harness wiring.

Easiest to try to spot the green-plug - cut adjacent zip ties or wire wrap tape with a diagonal clipper - frees up the 10"-12" wrapped up lead.

1) Can be up/under driver's side dash in same wiring area as the hood-release/OBD port

2) Can be up/under dash - on the cabin firewall - in the upper area behind the upper brake pedal mechanism

Good luck !
Just to tag on here as I installed a Tekonsha P3 last summer to tow a travel trailer. Remover the lower dash cover just under the steering wheel. Check to see if it is zip tied to any of the wiring behind the OBD port or in that area. Mine wasn't. Next, pull the carpet in the driver's footwell area. I spent 2 days looking and finally gave up. Went to the dealer and they ended up finding it under the carpet near the base of the gas pedal. Guess I did n't pull the carpet back far enough.
skw is offline  
Old 02-04-2017, 06:10 PM
  #8  
MBWorld Fanatic!
 
Join Date: Nov 2012
Posts: 4,941
Likes: 0
Received 574 Likes on 448 Posts
A gaggle of MB's
Yes - starting very-late-14's/15's + - yes it now can be under the carpet by gas pedal.

Remember - this controller plug is with factory installed hitch ONLY - no-hitch/aftermarket-hitch - no Green Socket
fabbrisd1 is online now  
Old 02-05-2017, 10:01 AM
  #9  
Newbie
 
Join Date: Dec 2016
Posts: 10
Received 1 Like on 1 Post
'14 GL350
Sorry to hijack this, but it is related. According to the user manual a 2014 GL with 360 Camera and a trailer hitch should have a view splitscreen option when shifted into reverse called "Top View and Trailer View" which shows a trailer coupling view. Can anyone confirm this? Pictures?
Ericlojo is offline  
Old 05-31-2017, 09:49 AM
  #10  
Newbie
 
Join Date: Jul 2010
Posts: 4
Likes: 0
Received 1 Like on 1 Post
2004 ML500
Help with brake controller connection

Originally Posted by Ericlojo View Post
Sorry to hijack this, but it is related. According to the user manual a 2014 GL with 360 Camera and a trailer hitch should have a view splitscreen option when shifted into reverse called "Top View and Trailer View" which shows a trailer coupling view. Can anyone confirm this? Pictures?
I can verify this, it has many camera angles including the overview of the hitch area with a line to follow.

Also, it you have the factory installed hitch, you will have the brake controller connection behind the carpet under the driver's side firewall at the bottom, its really down behind the brake pedal. As stated in an earlier post, you must remove the shield from below the drivers dash, pull the carpet back and then you can access. Its normally zip tied to a loop so it may be low but if you have the factory hitch, you have the connector. 4 wires, splice them into the pigtail and you're ready to go. I have done this myself on both ML's and GL's. Takes about 30 minutes if you know what you're doing.
ML_Lover is offline  
The following users liked this post:
Ericlojo (05-31-2017)
 

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Help with installing a wired brake controller!


Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: