Brake warning light while towing
Thread Starter
Junior Member
Joined: Jun 2010
Posts: 2
Likes: 0
Brake warning light while towing
Hello all. Truck is a 2012 F150, 5.0, 4x4. My BRAKE warning light comes on while towing. Not while braking. Just cruising down the highway. This does not happen ever when not towing. Brake fluid good. No issues at all without trailer. Also happens the same with any trailer I'm towing. Camper, boat, car hauler, etc. 7 way round, 5 flat, 4 flat. Warning light pops up randomly when towing anything. Thoughts?
Junior Member
Joined: Mar 2022
Posts: 13
Likes: 3
From: Chicago
I am thinking a ground wire or possibly the 7 pin connector or the harness to it. I have both go bad before and thinking while you are towing the bouncing and vibration of the road could cause the connector to loosen or loose connection. Also check the plug on the trailer to. Every year I usually put dielectric grease on the trailer plug and the plug on the truck just to help make a good connection..
in the house
Joined: Jul 2010
Posts: 5,140
Likes: 1,978
From: Kansas
Objective evidence indicates the problem is in your connector for the trailer lights. My wife had an Escape a few years ago that had this happen all the time, especially if it was wet out. Dealer tried multiple times to fix...I personally don't think they tried too hard...
Member
Joined: Aug 2018
Posts: 53
Likes: 2
From: Indiana
Same issue
Do you have a air leak noise when towing? Occasionally
my truck does the same thing only when towing but it only comes on when it receives a load like going up a hill. Never comes on when not towing. Also i notice a air leak of some sort from under hood i believe but the leak noise only happens when going up a hill while towing then shortly after i hear the hissing noise the brake warning light comes on.
ive replaced some of the vac lines coming off the brake booster and even the solenoid and check valve.
have you had any luck finding issues?
also this sound is hard to hear while traveling esp if windows are up.
my truck does the same thing only when towing but it only comes on when it receives a load like going up a hill. Never comes on when not towing. Also i notice a air leak of some sort from under hood i believe but the leak noise only happens when going up a hill while towing then shortly after i hear the hissing noise the brake warning light comes on.
ive replaced some of the vac lines coming off the brake booster and even the solenoid and check valve.
have you had any luck finding issues?
also this sound is hard to hear while traveling esp if windows are up.
Member
Joined: Aug 2018
Posts: 53
Likes: 2
From: Indiana
Do you have a air leak noise when towing? Occasionally
my truck does the same thing only when towing but it only comes on when it receives a load like going up a hill. Never comes on when not towing. Also i notice a air leak of some sort from under hood i believe but the leak noise only happens when going up a hill while towing then shortly after i hear the hissing noise the brake warning light comes on.
ive replaced some of the vac lines coming off the brake booster and even the solenoid and check valve.
have you had any luck finding issues?
also this sound is hard to hear while traveling esp if windows are up.
my truck does the same thing only when towing but it only comes on when it receives a load like going up a hill. Never comes on when not towing. Also i notice a air leak of some sort from under hood i believe but the leak noise only happens when going up a hill while towing then shortly after i hear the hissing noise the brake warning light comes on.
ive replaced some of the vac lines coming off the brake booster and even the solenoid and check valve.
have you had any luck finding issues?
also this sound is hard to hear while traveling esp if windows are up.
can anyone help me on this question?
Member
Joined: Aug 2017
Posts: 99
Likes: 10
Hello all. Truck is a 2012 F150, 5.0, 4x4. My BRAKE warning light comes on while towing. Not while braking. Just cruising down the highway. This does not happen ever when not towing. Brake fluid good. No issues at all without trailer. Also happens the same with any trailer I'm towing. Camper, boat, car hauler, etc. 7 way round, 5 flat, 4 flat. Warning light pops up randomly when towing anything. Thoughts?
Did you manage to find what the issue is? I'm having the same issue on my 2017 while towing. I predict either the connector the seven pin is getting loose or I have a vacuum leak somewhere as I just install the catch can 2 months ago.
Trending Topics
Senior Member
Joined: May 2015
Posts: 2,170
Likes: 640
From: Garland, Tx
Member
Joined: Aug 2017
Posts: 99
Likes: 10