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How do I Tell if the Brake Controller is Bad  


Should I get a continuous 12 volts from the blue wire lead in the back of the truck or should it only read 12 volts when I press either the brake pedal or the brake switch/slider on the brake controller. If I am getting 12 volts all the time is this a sign that the controller is no good.


Expert Reply:

You are correct, you should only be getting output when the brake is applied, or the override switch is activated. It sounds like the controller might be bad, but to make sure, you should probably bench test it before tossing it. Use a circuit tester, and check the red wire that exits the rear of the controller. This wire should only go hot when the brake pedal is pressed. If this checks out ok, then the controller is bad and must be replaced. We have a video that shows how to bench test a brake controller, I'll give you a link to the video below.

If you find that you need to replace the controller, I'd recommend the Tekonsha Prodigy P2, part # 90885. The P2 is a proportional controller for safer, more predictable braking. The P2 is very highly rated because of how easy it is to use.

expert reply by:
Mike L

Jordan W.


I took my Silverado 1500 ltz to the dealership because of the recall on the brakes. After I got it back. The trailer brake system keeps popping on. Even tho I never use the trailer brakes. They want to charge me 90 dollars to bring it in. Even tho the recalls where for the brake systems. Never had an issue until I got it back.

Etrailer Expert

Chris R.


My best advice here is to take the truck back up to the dealer. I can't imagine why they would charge you just to bring it in when a new issue occurred after they worked on the Silverado. I would try to argue this - they need to at least take a look to see if what they messed with is causing the trailer brake message to pop up.

Jordan W.


Funny thing is I got the recalls back in September of last year. Truck ran fine no issues with the brakes or everything. Around in May I decided to take it in and after I got it out I have all these issues now.Well now I have a stabilizer that's popping up. They told me that the trailer brake has nothing to do with the brakes itself thats why they wonna charge me. But I'm paying. I had no issues until I got it back from them.
Etrailer Expert

Chris R.


They're right that the trailer brakes run on a completely different circuit than the Silverado's brakes, but that doesn't mean it's impossible to knock a wire loose or do something else that may affect that function when working on the truck.

Duane L.


I have a 2021 Colorado with 3.6 cy, towing package. I do not have any voltage on F24 in the under hood fuse block that is supposed to be the positive for a brake controller. Even with the fuse out. Does the 2021 have to be programmed to power the fuse block?

Etrailer Expert

Mike L.


@DuaneL I believe that the F24 fuse is for the 12V feed to the trailer connector. Have you checked the fuse in location F27?

Rick L.


Your reply above makes no sense to me. You say the red wire should only go hot when the brake is pressed, and if this checks out ok then the controller is bad. Seems like you are saying if it works like it should then it’s bad?? I have a voyager xp brake controller. The green light comes on when connected to trailer. The green light goes red, and the trailer brakes engage, when pressing the manual slide. The green light stays green and I can’t feel the trailer helping my tow vehicle stop when pressing the brake. The fuses seem fine and my brake lights work. I am well within the year warranty so I tried returning the controller, but because I had cut the plug off, in order to hard wire it, they wouldn’t take it back. Tekonsha should include the other half of the plug, with pigtail, since their plug fits nothing, and because it forces people to cut and hard wire, which kills the warranty. Tekonsha told me to go on their website and submit a warranty claim. It wants a JPEG picture of the receipt. My iPhone pictures are PDF’s so it wouldn’t take it. I converted the picture to a jpeg file and it still wouldn’t accept it. So frustrating…

Jose P.


Hi Mike. I have a 2017 ram 2500 that factory brake controller might stop working my question is if a replace the module and toggle switch. Do I need to get the computer reprogrammed for the new controller. Thanks

Etrailer Expert

Mike L.


@JoseP You'd want to check with Ram about that. Typically when you install an OEM brake controller on a vehicle that didn't already have one you'll need to reflash the computer, but I'm not certain if that's the case when you replace and existing OEM controller.

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