Another trailer light question

[ronchp]

We recently traded a Sundowner horse trailer for a 2013 Exiss trailer with finished dressing room. We pull it with a 2015 Chevy 2500 HD. When I plug the trailer lights into the truck receptacle, it turns on the running lights on the trailer and truck and they won't go out until they are unplugged. The Sundowner trailer did not do that-the running lights only came on when I turned them on. The brakes and turn signals operate correctly. Only reason I'm concerned is if I forget to unplug them then the battery could be discharged. Any idea how to correct? I am not very knowledgeable when it comes to electrical circuits.

 

[robstaples]

If you have pin 3 and pin 4 on a seven pin trailer plug reversed, you would get your result.
See trailer 7 pin layout - Google Search

What plug format do you have?

 

[WM75Guy]

With them reversed if you have a battery on the trailer it is not getting charged unless you have the running lights on the truck on.

 

[MinnesotaEric]

Your trailer wiring harness goes into a box?

Yes? Then a wire is likely crossed in the box or the wiring itself is chaffing somewhere.

 

[ronchp]

Great info. Probably won't have an opportunity to check wiring for a couple of days since rain is in the forecast. As soon as I get a chance, I will see if pins 3 and 4 are swapped. Or to Eric's point, maybe they are shorted together somewhere. I'll let you know in a couple of days if I can get it corrected with this info.

 

[Redlands Okie]

At one point in time dodge wired different than ford on the plugs. May still do for all i know. The running lights and electric brakes would always be crossed. Plug goes in and the brakes would activate. Bought a factory made adapter so I could easily pull rental trailors and equipment from some local companies. So as said above you probably have a wire crossed.

 

[ronchp]

Had some time to work on it. This is going to take me awhile to get straightened out, but at least I now understand the problem.

Found that pins 2&3 were shorted at the plug so went to the terminal box and disconnected them and traced the short to inside the trailer. Inside the trailer I found 2 spots where someone had spliced the wires together for some reason and that is as far as I got. Guess I will disconnect the splices and go from there.

 

[Btown]

That's good you found the problem. Now let's hope it's not too hard to fix.

 

[TomSeller]

Hooked my utility trailer up today to my flat 4 connector and had to plug it in twice to get running lights to operate. It did the same when I rented a Uhaul trailer a few weeks back. Anyone know if they make plug connector cleaners like a battery post cleaner? With male and female ends with wire bristles.

 

[r porter]

we had an exiss once that had a wire ran over a frame member on the floor. by being over the frame it was under the aluminum floor so it would pinch with a horse on and short out.

 

[r porter]

an old brass cleaning brush chucked up in a drill will do the job nicely. a 22 cal or 6mm should fit.

Hooked my utility trailer up today to my flat 4 connector and had to plug it in twice to get running lights to operate. It did the same when I rented a Uhaul trailer a few weeks back. Anyone know if they make plug connector cleaners like a battery post cleaner? With male and female ends with wire bristles.

 

[radioman]

i find that with 4 way flat plugs they just dont last. the grounding prong always seems to break off. replacing it with another 4 way solves it for a few years then its back. i ended up installing a 7 way rv plug and its been super reliable since. best thing i ever did.
an added plus is that its harder for someone to borrow my trailer unless they have a 7 way. :thumbsup:

 

[sdef]

If the previous owner wired it this way and used it successfully--sometimes it is just easier to rewire than to find a short hidden somewhere or to fix someone else's mods that lead to an abyss. Trailer lights are pretty easy to rewire/replace on most anything.

 

[Fallon]

If the previous owner wired it this way and used it successfully--sometimes it is just easier to rewire than to find a short hidden somewhere or to fix someone else's mods that lead to an abyss. Trailer lights are pretty easy to rewire/replace on most anything.

Yup, that's my usual solution. Do it right & put in LEDs. Wire isn't cheap, but it's cheaper than my time & sanity. I wire everything up as a 7 pin RV style regardless of what it was previously too.

 

[TomSeller]

i find that with 4 way flat plugs they just dont last. the grounding prong always seems to break off. replacing it with another 4 way solves it for a few years then its back. i ended up installing a 7 way rv plug and its been super reliable since. best thing i ever did.
an added plus is that its harder for someone to borrow my trailer unless they have a 7 way. :thumbsup:

From time to time I need to rent a Uhaul trailer with a flat 4, I guess I could have a 4 way to 7 way adapter.

 

[Fallon]

Have a 4/5 & 6 way adapter for those scenarios They are only $20 or so & give you lots of options.