12 Volt Power on the Brake Output Pin All the Time On 7-Way Trailer Connector on 1998 Ford Explorer

Question

Question:

I have a 7-way RV plug installed on a 1998 Ford Explorer. While rewiring the plug and testing it, I discovered that I have 12 volts of power on both the black wire, which I expected, but also on the Blue trailer brake wire. This was the case without the brake pressed or the manual trailer brake actuated. I was wondering if this is normal. Bottom line, is it normal to have power on the blue trailer brake wire on the vehicle side of the plug when nothing is connected and no brake manual or brake pedal is applied?

asked by: Leroy K

1

Helpful Expert Reply:

There can be a very small amount of power on the brake output circuit of a 7-Way (5:00 position) which would be the brake controller checking for a trailer, but there should not be 12 volts of power. That indicates a short of some kind or a problem with the brake controller. Since you said you recently added the 7-Way it is possible that inside the connector where the wires attach the 12 volt circuit wire is touching the brake output circuit causing the constant draw.

If you address that issue, if present, and you still get 12 volts on the brake output circuit then the likely culprit is the brake controller. To test the brake controller, sever the blue wire a few inches back for the back of the controller. Then use your tester to test the end coming out of the controller. It should only show power when you apply the manual override. If it shows power at any other time then there is something wrong inside the controller and it will need to be replaced.

I have included links to our wiring and troubleshooting brake controllers FAQs for you as well.

expert reply by: Michael H

1

Answer 1

The issue sounds like it is in the wiring going from one side to the other side. First, you may need to switch to a larger gauge wire such as #10-1-1. But given how you have been testing and the results you are seeing there should not be that much…

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Answer 2

You have definitely done a great job narrowing down the issue. Because you have adjusted the brake assemblies and tested the manual slider output at your 7-way, we know there is a voltage issue. This can be from a weak ground connection or a power…

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Answer 3

The only pin that should be continuously showing 12V power on the 7-Way connector on your vehicle is the 12V power circuit which is normally the black wire but not always. In 7-way wiring the 12V auxiliary power feed is carried on the contact at the…

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Answer 4

If you are receiving no power at the receptacle but you are receiving power at the bumper 7 way connection then it is unlikely it is a blown fuse. More than likely it is a damaged wire or a bad connector, to determine this start by tracing the black…

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Answer 5

Since you just installed the #AKEBRK-35-SA on your trailer and are experiencing this issue, the most likely cause is just a weak ground wire on the right side. I recommend checking the wiring on the side that is providing weak braking (the right side…

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Answer 6

The AX (Auxiliary) location on the Hopkins 48505 connector that you reference, which is the same one used on the Hopkins #H20046, is typically used for 12V power. If you take a circuit tester like part #PTW2979 or #C73NR you should see that the…

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Answer 7

Most brakes also require a (break-in) period. Dexter says to get up to about 20-30 mph and use the manual override several times. They may also feel weak breaking because it is recommended to let the brakes (seat) into the hub for the first 200 miles…

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Answer 8

Since you are not getting the 12V power when your truck is running, you most likely don't have a fuse issue as you stated their isn't a specified fuse or relay in the owners manual. The issue is that your truck is computerized even at the…

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Answer 9

On each individual electric brake magnet the amperage draw would be 3.0 to 3.2 max amps at 12 to 13 volts on 7-inch brake magnets and 3.2 to 4.0 max amps at 12 to 13 volts on 10 and 12-inch brake magnets. The max amperage draw for the brake magnets…

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Answer 10

Since you are exceeding the trailer's gross vehicle weight rating (GVWR), the braking power is surely to be compromised. I would first recommend increasing the gain on your vehicle's brake controller. This will help to increase the braking…

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Answer 11

Typically trailers will carry more of their weight on the front of the trailer, so you would want to put the brakes on the front axle as it will most likely carry more weight while braking. Also, when braking, weight will shift forward from the…

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Answer 12

The Dexter Nev-R-Adjust electric trailer brakes can be manually adjusted. There are a couple teeth of the adjustment wheel that are exposed just under the lever that you referenced. I have attached a photo showing the teeth. You will likely need a…

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