Troubleshooting Low Voltage Output from Brake Controller

Question

Question:

Ive checked all my connections at the controller and verified the voltage - Ive got 12v coming in at black wire, 12v coming in on red with brake pedal pushed, 12v going out on blue wire when brake is pushed and when manual override is being used. At the trailer connection point on rear of vehicle I am only getting about 2.5v for trailer brakes. I have cleaned the connections on the vehicle but doesnt seem to change that I am getting low voltage. I also tried to ground directly to the vehicle instead of using the vehicle plug and it is a consistent low volatage at 2.5 volts. Ideas? Thanks

asked by: Seth

0

Expert Reply:

Something is obviously causing a voltage drop between the brake controller and the trailer connector. The usual culprit in this type of situation is a break in the wire or a corroded wire. Check the wiring under the truck. You should be able to trace the trailer connector wires from the back of the trailer connector up toward the front of the truck. Look for any sections that look like they may have been pinched, frayed or even eaten through. If there are any wires spliced in or quick splices, remove those connections to look for corrosion.

If everything seems to check out okay, you could bypass the factory brake output wire and run a separate wire using something like # 10-1-1. Cut the blue wire exiting the brake controller about 6 inches back, splice in the new 10 gauge wire and run it to the trailer connector. There should be a grommet in the firewall that you can use to run the wire into the engine compartment and under the truck. Be sure to avoid moving parts or parts that get hot.. Next, locate the wire that goes into the 5 o'clock pin in the trailer connector and cut it a few inches behind the trailer connector. Leave enough length to splice-in the wire from the brake controller. This will fix the problem if you are getting a 12 volt output at the brake controller.

expert reply by: John H

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Answer 1

It sounds like you are speaking of the wires for the brake magnets. If this is correct, you will need to connect one of the wires to the brake controller output wire on your trailer connector and the other wire will need to be grounded to a clean…

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Answer 2

The traditional wire colors for brake controller installation are white for ground, black for 12 volt power, red for stoplight switch, and blue for brake output. For more information on wiring in a brake controller check out the help article I…

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Answer 3

It should be getting close to 12 volts if the power output is set to the maximum on the brake controller. Some brake controllers will not work properly if they are titled or turned to the side or if it has a leveler knob that is not level. Check…

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Answer 4

You will indeed need to install a 40 amp fuse in position 68 to activate stud 1 that powers the 12-volt accessory power circuit to the trailer connector. If there isn't already a wire connected to stud 1, you'll need to locate the red wire…

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Answer 5

We do offer all kinds of replacement brake parts for both electric and hydraulic drum brakes, including shoes, springs, actuating levers, etc. But many folks do determine, after reviewing all the parts needed and their total cost, that the time…

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Answer 6

If you are only getting 1.5 volts at your brakes then there is an issue, but there is not a fuse that controls the brakes. There are a number of possible issues so you will need to find out if the issue is on the brake controller, truck, or trailer.…

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Answer 7

There are a number of reasons why the brakes on your trailer may not be working. Lets start with the easiest things to check. First, check the vehicle and trailer connectors for corrosion. This can cause a short inside the connector and the brake…

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Answer 8

More often than not, the connections under the hood of your 2010 Chevrolet Silverado 1500 will need to be made to complete the installation for a brake controller. I have heard of some occasions where these connections were made at the factory, but…

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Answer 9

I believe you almost solved the problem when you swapped the wiring, but in reality you needed to use 10 gauge wire like part #10-1-1 (sold by the foot). You are experiencing a voltage drop due to the long distance of wire that's not thick…

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Answer 10

First of all did this problem just start happening? If the trailer has always worked fine before on the same truck then it's likely a short on the trailer's brake wiring. I would start by cleaning the connector and make sure it's free of…

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Answer 11

No, the brake output circuit of the 7-way on your truck should not be showing 12-volts when the brakes aren't applied. This circuit should have no voltage unless the brake controller is activating either with the manual override lever or by…

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Answer 12

There are many things that can affect the voltage on the brake output wire from your brake controller to your trailer brakes such as the power setting on your brake controller, how you are testing the wire and if you are testing it with the brakes or…

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