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Hot Wire for 7 pin connection

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Just got a new horse trailer that has various flood lights that don't turn on. Someone said that my plug isn't wired for the "hot wire" in the center pin... anyone know about this? I do have everything else (brakes, running lights, turn signals)

thanks

Forrest
 
Check in the fuse box under the hood and make sure there are no popped fuses. Your truck should have a hot wire on the trailer plug.
 
There should be a 40amp (if i remember right) fuse under the hood, check that one. If that isnt it, check that 12volt is supplied to the truck end of the plug... it should be hot at all times. However I do not think factory wires for center hot... center on mine is not used, I used to use it for back up lights... but neither of my trailers have them now.
wiring diagram
a simple voltmeter works wonders on trailer plugs... keep in mind though that the trailer is not necessarily wired to the same pin config as the factory...
 
Check for voltage at the #4 terminal in the truck receptacle, it should be the one that supplies power to the trailer/charges the trailer battery and is a 10 ga. versus the #7 center wire which is only a 14 ga. bg
 
. . . Someone said that my plug isn't wired for the "hot wire" in the center pin... anyone know about this? . . .
If you have the OEM trailer wiring the center pin is backup lights.

A look at the cover of the OEM receptacle should give you everything you need—it has a molded diagram indicating the function of all seven contacts.
 
yes back ups, put another switch in the cab tied into the back up lights switch in the transmission... . and you will have power.
 
If your truck has the factory wiring and your trailer is brand new, take the trailer to the trailer dealer and tell them to wire it right. Your '02 should be wired the same as my '01 was and my '04 is, and that is "industry standard".

Anything else is not right and will cause you problems if you ever need electrical work done on the road somewhere.
 
AB, I was getting ready to get all bent out shape because these same lights didn't work on my nag wagon. The culprit? Just a little spider web up in the plug!! Mark
 
thanks for all the replies. I did notice that the center pin is backup lights according to the plug cover on the truck. My buddy has an 07 that he pulls a sundowner with and all his loading lights work. Plugged my trailer to his truck and nothing happened, my trailer is 4 years newer and a different brand (its a Bloomer) than his so may be wired different :confused: Am going to the dealership to get the floor padded and I'll have them investigate this. Oh yeah, I did check all the fuses/relays under the hood and they seem to be good. Trailer lights are never easy!

Forrest
 
trailer wiring isnt too bad, just have to isolate the issue... the first thing I would do is get a voltmeter, and verify you have voltage to the proper poles on your truck plug. if you feel like tinkering with it before the dealership: I would look and see if there is a junction box where the plug harness goes into the individual wires that run throughout the trailer. If there is a terminal box it could be easy enough to check for wiring config, some newer trailers use a molded plug, but if it is not molded you could take the plug apart and verify wiring on the trailer plug colors match the schematic for industry standard... colors are not 100% either, some swap a couple around, but would help to know this if it is the case. take a look at the wires going to the loading lights, the color supplying them should stay the same throughout the trailer, and then check that this wire makes it to terminal... if I am in doubt i use a battery charger or other power supply to apply voltage to individual wires and see what lights up.
All it takes is time and patience, and a mulitmeter helps.
 
Just got off the phone with the dealership and they told me that the accessory fuse to the hot wire is pulled out; which is the way they come from factory. I'll see if I can figure it out and get them working this afternoon.

Forrest
 
So i did as the trailer dealer said and no fuse for trailer auxillary on my truck. Apparently only on GM's and Fords, not Dodges (looked on my buddies '07 to make sure). The Dodges come with the center wire hot only when back up lights are on (as the cover shows). So i turned on my back up lights and still nothing :confused: The Trailer came with a folder full of papers so I start shuffling through and find a wiring diagram. Highlited in a box off to the side there is a statement that the auxillary wire is to be connected by the company that does the living quarters, not the manufacturer of the traielr... My trailer came with an unfinished dressing room, no living quarters... figured I should check out the junction box. Sure enough, the hot wire coming in off the plug was wrapped in electrical tape, not connected. So I unwrapped it and made the connetion and I have lights! So now I just have to change the plug so that wire is always hot.

Forrest
 
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