Question about 2003 GMC Sierra 1500

1 Answer

Constant voltage on brake controller pin at connector.

I have a 07 chevrolet silverado 1500 that came with tow package. I took it to the dealer and had a brake controller installed. The pin on the connector for the brakes shows four volts all the time, even with the truck off. it does not change when the brakes are pressed. I am worried that it will keep the brakes on my travel trailer engaged all the time. Is the constant voltage normal? this was the second controller that I got. I wired the first one and had the same problem, so I took it to the dealer.

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.


    An expert that hasĀ over 10 points.


    An expert whose answer gotĀ voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 19 Answers

You should not have voltage unless you apply the brakes on the vehicle or the brake controller. the only constant voltage you should have is the charge line on the 7-way.

Posted on Jul 16, 2009

3 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

SOURCE: 2005 2500hd silverado 4x4 factory

you have to put the fuse in to make it hot

Posted on Aug 12, 2008

  • 51 Answers

SOURCE: I have a 07 chevrolet silverado 1500 that came

Call the dealer and tell them your concerns so that they may troubleshoot and correct the problem. They should have checked it themselves to insure they did a proper job.

Posted on Jul 16, 2009

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Towing capacity of 2002 silverado 1500

Look in your owner's manual, or on door post info sticker.

Oct 21, 2012 | 2000 Chevrolet Silverado

2 Answers

Truck won't shut off until I unplug my tent trailer? Just pick up new trailer and had a 7 pin connector added to my truck along with a brake controller

It sounds like someone messed up to me! Apparently, the brake controller got wired into an ignition circuit that it should not have gotten wired to. When accessories are added to a vehicle, it is extremely important that the vehicle wiring diagrams are used so that you know EXACTLY what you are tying into. Some of the Chevy trucks that are sold with trailer towing packages already have the wiring for brake controllers under the dash. This makes installation easy and is already tied into the correct things.

Also see my comments on related subjects HERE

Apr 05, 2011 | 2002 Chevrolet Silverado 1500

1 Answer

My 1999 Silverado has a dealer towing package installed but not the brake control. The truck wiring recepticle has the blue wire running into the wiring harness going to the front of the truck. Any idea...

Hello af4lb.

Usually you will find this wire taped up to a harness just behind the underhood fuse panel.
Follow the large harness up from where it goes to the rear under body and it should break out of the harness there. You may have to slide some tape back to see it.
I hope your search goes well.
Thank you for using FixYa and have a happy New Year.


Jan 01, 2011 | 1999 Chevrolet Silverado 1500

1 Answer

2009 Silverado 4x4 pickup with towing package and factory installed Trailer Brake controler installed at factory. The system has worked in past. I had my Stock trailer rewired and things tested out fine...

It sounds like you lost a ground.
check traier hookup first.
Probably not the controller.
P.S. There are multiple fuses for this setup. check all ! ! !

Aug 19, 2010 | 1999 Chevrolet Silverado 1500

1 Answer

Brake contoller showing 4 volts on the connector pin all the time

If the controller uses a SCR to switch the power on to the trailer brakes there can be some low voltage leakage across it. If you measure the amperage I would guess it's milliamps.

May 22, 2017 | Chevrolet Silverado 1500 Cars & Trucks

1 Answer

I have a 07 chevrolet silverado 1500 that came with tow package. I took it to the dealer and had a brake controller installed. The pin on the connector for the brakes shows four volts all the time, even...

Call the dealer and tell them your concerns so that they may troubleshoot and correct the problem. They should have checked it themselves to insure they did a proper job.

Jul 16, 2009 | 2003 GMC Sierra 1500

2 Answers

Low voltage to fuel pump

there is a factory bulletin on this problem, it is the connector to the pump module, they get overheated, the pins loose good contact and u get low voltage, there is a repair connector availiable from GM and from a Company called Airtex
AIRTEX Part # WH3005 {Wiring Harness; 1x4 Spade Style Connector}
Wiring Harness replacement recommended. Price at $8.93

Jun 04, 2009 | 1999 Chevrolet Silverado 1500

1 Answer

Brake controller not communicating w/ 7 pin connector

what type controller did you install? Is this a camper or trailer? Is the controller hydraulic plumbed into master cylyder? Important to know how to adjust rheostat for sensitivity. If set at minimum the system is basically on the edge of not sending any signal to towed unit. The intructions should explain how to make this adjustment. If set too sensitive trailer brakes will lock up before the tow vehcle starts to brake. Controller should be set so trailer starts braking just befor the tow vehcle. If not the trailer will tax the tow vehicle brakes by pushing. Its set right when you feel the combination stretching out. trailer first then tow vehcle. Good luck and remember, if truck brakes first and too hard you risk a jacknife. All light voltages should be system voltage. Brake voltage is variable depending on setting on controller. Understand your breakaway brakes and how they work. breakaway breaks require an auxillary battery. Again, good luck and you know where to find me if I can be of anymore help.

Apr 13, 2009 | 2003 Chevrolet Silverado 2500HD

1 Answer

No brake lights ,fuse is good,brake switch checks good. 1998 chev

Have you Checked the Harness under the Rear of the Bed for the Tow Package? These Truck usually have the Plug Harness installed from Factory and can sometimes come Undone.

Dec 31, 2008 | 2001 Chevrolet Silverado 1500

1 Answer

Towing package

Did you get any directions w/ brake controller? On Some vehicles you can't connect wires of the same color from vehicle to controller, they use a different color code for the wires, so it may be a wire connected improperly, even though all the colors match. countrycurt0

Sep 09, 2008 | 2004 Chevrolet Silverado 1500 Crew Cab

Not finding what you are looking for?
Cars & Trucks Logo

235 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts


Level 3 Expert

75744 Answers


Level 3 Expert

1311 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22114 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides