I am having a problem getting two wires to work on my trailer wiring. The battery charge and the Auxillary are not working for some reason. I have already checked under the hood at the fuses and relays and all check fine. I know the rest of the wires are correctly wired. Does anyone have a wiring diagram for the trailer wiring? Or is there another way I can get these wires to work? 2001 F350 DRW 4WD

 

Are you talking about the + on the plug in?IF so the key has to be on to put power to it.

 

Yes, I have checked with the key on and the truck running also. It is the battery charge wire for the 7 pin round plug. Also the Aux wire is not working.

 

you need to access the under hood fuse box (drivers side near the fire wall behind the air filter housing) you need to put 2, 30 amp maxi fuses in the box (locations 16 and 28) and 2 relays in the small relay box right next to the fuse box (they are not there from the factory)

 

Nova,

I know you said everything "checked good" under the hood, but....

Did you use the factory "pigtail" adapter from the truck's wiring to the trailer plug? This is the one that has both the four-pin and seven-pin plugs.

If so, then be sure that you have the "doghouse" relay box installed. This came with the trailer wiring kit. It is the one pictured below without its cover.

BTW, what do you expect to be on the "AUX" pin when you're done?

I know how frustrating this can be, as I went through this same thing when I installed my rear plug, too.

Pop

 

if you cant figure it out i have a PDF of the wiring schematic...send me an E-mail and i will send it to you

 

After looking under the hood again the fuses are all there however I am missing one relay (the one furthest from the firewall). Anyone know where to pick one up?

 

I had replaced the original pigtail with a newer one since the old one was damaged. The plug is still there and the new pigtail was spliced in according to proper wire function. The AUX will power all the interior lights (3 of them) for my horse trailer.

 

they are standard 12 volt automotive relays, any auto parts store should have them. they normally come with a mounting tap attached to them, you will have to cut that off so it will fit in the box.

ps. check your e-mail i sent you that schematic

 

What is the purpose of these 2 relays anyways??

 

the front one is the "trailer tow backup relay" and the rear one is the "trailer tow battery charge relay"

 

I will check the relays and see if I can get power to the wires in the back. Thanks for all the help.

 

Well after the relays were put in there is still no power to either wire. I am wondering if my brake controller might have something to do with it? Not sure that it is wired right, I know it works except when I push the slider to apply the brakes manually it doesnt apply any brake voltage. I will have to try and trace the wires back to see if there is a break in my wire somewhere. Thanks everyone.

 

Ok, both relays check good, I am now getting power to the AUX wire. But still not getting anything to the Battery recharge. On another truck when you turn the ignition key on the relay closes, when you start the truck the relay temporaraly opens and when the truck starts the relay closes again. On my truck the relay closes when the key is turned but when you start the truck it stays open. Not sure why. Anybody have any ideas as to why it does this?

 

Well after an hour or so trying to figure this wire mess out I decided to cut all wires and start over. With the wiring diagram I recieved from wlihntr I spliced everything up and wala... it all works now. Not really sure what wires I had crossed but oh well everything is fine now. Thanks everyone...