power going to the trailer brakes all the time ??

ncjeeper76

ncjeeper76

Active Member
Joined
Jun 4, 2006
Location
Climax NC
I just changed the trailer plug on my 89 F 250 from the 6 pin style to the 7 pin(blade) style. The only thing is that there is power on the blade for the trailer brakes all the time even with the truck off. I checked the wiring everything seems to be hooked up right. It had the controller in it when I got the truck and it uses the factory wiring harness. Is this normal ??
thanks
Jason
 
you have 2 wires crossed most likey, check which blade, truck side, is EB (elec brakes) then find it corresponding on trailer side and move pin wire accordingly. looking at truck, pin EB should be on the right side of the plug slightly down. this would make it correspong to most other trucks and trailers but not always. the reason why you have power to the brakes all the time is probably you have a aux. wire going back there this is connected straight to battery to power a trailer winch, ect. ect. if you swap this aux wire w/ your brake wire you will probably be right then.
 
It is not normal. Without the lights on none of them should have power all the time except the center connector and that's optional.
 
x3
Elec brakes should not have constant power.Some vehicles have the pin layout imprined on the plug cover.
 
the biggest problem i think is that its not clear as to the orientation on the plug. Its easy to reverse the patter since your actually looking at the plugs from the back when you wiring it.
Here is a pic from the etrailer web site that shows the correct wiring AND reference how it should be viewed.. (the web page indicated your viewing the BACK of the plug not from the front.)

g3500.ref.elec.wiring_7_pole_500.jpg
 
And just to point out... There really is NO set standard on this stuff. Thought the auto mfgs have sorta standardized in the last few years, on the pic I posted... The Aux vs 12v wire is really up to you. The AUX is usually used for reverse lights. but some ppl swap that to the side, but if you don't have reverse lights or a bat to charge it won't matter..
 
Thanks

Thanks for the info guys. from what I have found. It seems that the controller I have puts out 12 volts at a very low amprage. I ran the bench test and everything checked out
thanks
Jason
 
did you use an adapter? If you did I have had a LOT of them(The adapter) that are wired wrong come into the shop lately!
Later,
Bradley C
 
theres a light on my controller thats always light up when the trailer is connected, then when you apply the break it then displays the power that i have set for the brakes.
 
Ford 6 pin round uses center pin for brake, other trucks use center for power and side for brake. If they wired it based off where the wires were on the 6 pin, probably just crossed the brake with the constant power (like to charge RV batts).

When you buy the 7 pin to 6 pin adapters, they have an instruction in there about center pin power for Fords and how to switch it.

Ran into this a few times when towing trailers wired for my pop-in-laws old dodge. Put it on my ford with his adapter and was dragging the tires on the trailer as they were locked solid.

But like someone said, standards are a loose term. Really depends on the place the wires the trailer and truck. They can do whatever they want as long as it works on that vehicle when it leaves their shop.
 
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