Trailer lights aways on

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Apr 1, 2011 | 05:09 PM

canonsue

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Trailer lights aways on

I have a 2011 Ford F-150 XLT. Thanks to the forum, I did take the fuses out of the glovebox and installed them. So trailer lights and blinkers work fine. I just purchased a small teardrop tailer. My problem is that the trailer lights are always on when plugged into the truck.They are on even when lights are off and key is out.

I am assuming that the problem is with the wiring of the trailer harness but I wanted to ask here first in case the problem might be with the truck. I have never had a trailer so I am unsure if the 7 prong plug is always hot. Obviously it is on my truck. Is this way it should be?

What do you think may be the problem?

Thanks,

-Sue

Apr 2, 2011 | 10:12 PM

Rancheroracer

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From: Rodeo, Ca.

The 7 pin plugs typically have a + and a -, (12v pos & 12v neg). Sounds like the trailer plug is wired wrong.

Apr 2, 2011 | 11:38 PM

LxMan1

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From: Louisville,Ky.

Usually the BATT + is only hot with the key on. My 01 F150 was that way. I used it to charge the battery on my car trailer for my winch.

Apr 2, 2011 | 11:50 PM

MisterCMK

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From: Blue Hill Township

Quote:

Originally Posted by LxMan1

Usually the BATT + is only hot with the key on. My 01 F150 was that way. I used it to charge the battery on my car trailer for my winch.

The Chevy trucks have the charge wire hot all the time.

Apr 3, 2011 | 07:25 AM

canonsue

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It looks like the truck is the problem. A circuit tester shows that when the key is turned on both the power and the lights circuit is powered. It should only show that the power is on. I also hooked up my trailer to another vehicle and it worked correctly. Some how there is a feedback circuit that when the trailer harness is plugged into the truck and the key is out, the trailer battery lights up the running lights. Now I just need to convince my Ford dealer of the problem so I can get a warranty repair.

Thanks for all of the responses.

Apr 3, 2011 | 04:50 PM

LxMan1

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From: Louisville,Ky.

Quote:

Originally Posted by MisterCMK

The Chevy trucks have the charge wire hot all the time.

I don't like that!! Fire hazard, plus you can get feedback from the trailer battery. I guess that's another reason I will never own a GM. Ford and Dodge have the better idea here.

Apr 3, 2011 | 05:22 PM

MisterCMK

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Joined: Mar 2003

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From: Blue Hill Township

Quote:

Originally Posted by LxMan1

I don't like that!! Fire hazard, plus you can get feedback from the trailer battery. I guess that's another reason I will never own a GM. Ford and Dodge have the better idea here.

My biggest beef with that is that you can discharge the truck battery with a trailer hooked up. Then you are pooched.

It would be nice to have a timer or something like that to turn on the charge wire for a little bit but I suppose I could get off my duff and put a battery in the enclosed trailer to run the lights too. lol!