Ok guys heres my delima,

About 2 weeks ago my trailer interior lights quit working. I dismissed this as an issue with my trailer. After checking everything humanly possible on the trailer and getting the lights to power up and work fine i determined it was issue with my truck. I started checking fuses on my truck every fuse that my manual list for the trailer checks out fine. My truck does not have the factory tow package as far as i know. I put my own 7 pin connector on the truck and put my own brake controller on. I thought at first i had an issue with the plug so i started probing the wires before the 7 way. I have power to all my lights, and to my brakes everything works except for the interior lights. I called the manufacturer of the trailer and they informed me that the trailer lights are powered by the 12+ pin on the connector. I started checking everything with the plug on the truck and i get NO JUICE at the 12+ pin(yes the ignition is on). The only thing that i can figure is that the relay for the charge has gone bad but i have NO IDEA where this is located under the hood, My manual does not tell me where this relay is can someone please help me out i really need this pin to work it charges my break away battery and it runs my interior lights im going nutz trying to figure out why i lost power to this pin i have wasted about 6 hours trying to get this working and i have come to the conclusion that the relay is bad but like stated before i have no idea which one is the trailer charge relay !! Thanks for all the help and sorry for the long post.

John

 

Well, I'll take a stab at this.....

The 12v charge FUSE is # 16 on my 1997 F150 in the under the hood fuse box. It's a 40 amp fuse. It's also the stop/turn lamps fuse too.

The 12v+ pin on the 7 pin is the one at the ~ 1 o'clock position while looking at the plug on the truck.

I'm actually not sure on the relay setup anymore.... As I look closer at mine, I have all the relay slots filled up.... My manual states that;

#1 is the interior lamps relay.
#2 is the battery saver relay.
#3 is not used (but I've got a relay in that slot??).
#4 is one touch down relay.
#5 is the accessory delay realy.....

Not sure what #6 is, but It's got a relay in it too???

The numbers on the relays are basically the same too....

1-3 are smaller relays and have "F57B-14B192-AA" stamped on them.

4-6 are larger relays and have "FOAB 14B192-AA" Stamped on them.

It sounds like you know the pin locations and know what to check.... You might try tracing the 12v+ wire back to each harness connection and see if it's one of those connections that you lose power on??

Good luck!

Mitch

 

Next to my main power box under the hood there is a box full of relays(probably 8-10) i cant remember how many, but there is absolutely no mention of this relay box in my manual? im almost positive that my trailer relays are in that box. If i can find the relay im going to replace it thats the only thing it can be. fuse#2 in the small little hidden box is good, fuse #23 in the main box under the dash is good, fuse #16 is good, like i said every fuse that my manual list checks out but im positive its this darn relay. Im about to just run a constant to the back of the truck from the battery but i really dont want to be rigging stuff i really want this to work with my factory stuff i appreciate the reply hopefully someone can tell me what this other relay box next to the main distro box under the hood is like i said there is about 8-10 relays in there and i dont know what they are !!

 

that relay box next to the main one is the one that is not listed in my manual does anyone know exactly where the trailer relays are?

 

see the sticky at the top of the section

 

Hey 36,

If that sticky post is the fuse box under the hood on the drivers side, then it's not even close to what the arrangement is for a '97.....

Mine is exactly has JH's, except the smaller, single box with the row of relays is different from my F150.

Mitch

 

Have you tried swaping relays? See what will not work after switching one relay for another. Just keep track which one came from where and only swap the same type. Or you could buy an relay and swith it out one at a time until you get your problem solved. They can't cost too much.