'98 Explorer XLT 5.0 Trailer Wiring HELP! | Ford Explorer Forums - Serious Explorations

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'98 Explorer XLT 5.0 Trailer Wiring HELP!

Ah, where to begin. Mods, feel free to move this if this isn't the right spot to post this topic. Also, feel free to delete this if it has been covered somewhere, I'm just not seeing it and it has become very frustrating.

Let's begin. Just like the title says, it's a 98 XLT Ex 5.0. I recently got my hands on a new to me trailer and naturally need a place to plug the lights in. Trailer has a 7-pin connector with only the green, yellow, brown and white wires in use. Ex has never had trailer lights wired but has a new 2" receiver installed underneath. Upon my initial research I learned the first thing to do was to locate the factory plug behind the drivers side taillight. Done. Ordered the harness to go from ford plug to flat 4 and made an adapter to go from flat 4 to 7-pin. Done. Connected everything, turned on the three way switch for the lights on the dash, lights everywhere except on the trailer. Bummer! Now what? I keep reading about seperate relay boxes number 2, number 3 whatever and cannot find any more info on where they are exactly and what I should be looking for. Fuse 3,7 and 30 in the fuse panel on the side of the dash are all good and the owners manual doesn't list anything remotely close to the words "trailer" or "tow". I did some tests on the plug behind the taillight and found 12v power between two of the pins but got a negative reading on a third and nothing on the fourth. Don't know what colors they were off hand and don't know if I was even checking them the correct way to be honest. Is there something I'm missing here? Some other test I can perform to narrow this down a bit better? Any help would be appreciated.
 






auxiliary relay box #2

According to the wiring diagrams for my 2000 Sport the Auxiliary Relay Box #2 is located at the left rear of the vehicle, above the wheel well. I can't tell from the drawings but I think the relay is behind the removable panel where the jack is stored at the top front.

The following thread should be helpful:trailer plug ripped off..need color code
 






According to the wiring diagrams for my 2000 Sport the Auxiliary Relay Box #2 is located at the left rear of the vehicle, above the wheel well. I can't tell from the drawings but I think the relay is behind the removable panel where the jack is stored at the top front.

The following thread should be helpful:trailer plug ripped off..need color code

WOW! There is all kinds of tips and tricks there I wanna try. Thanks!

I know how to test my wires the correct way now and also I think I might run a wire from 12v to the brown/white wire and see if I have lights like this. Then I'll go from there.
 






Ok, tested the truck tow wiring. Placed the running lights on at the three-way dash switch and turned the hazards on. Grounded to the chassis and tested the stock trailer wire plug from behind the drivers side taillight. I've got power to the left turn pin, the right turn pin and running lights pin. Good to go there. Plugged in the factory harness I ordered to go directly from the stock plug to flat four and tested there. Still good. Attached the harness I made to go from flat four to seven, good there too. All the pins are showing power where they're supposed to be as well. Plugged in the 7 pin from the trailer and no dice. The trailer had lights before too so I know there isn't an issue with the trailer wiring that I know of. The trailer plug is another story. Someone had ripped the plug off the wire on the trailer and they rewired it according to the labels inside the plug. TOTALLY wrong! They aren't labeled even remotely close to what it should be. I had rewired the plug correctly (or so I thought) and had continuity between the brown/yellow/green and the ground. Well, after double checking continuity on the plug again, guess what, its backwards LOL! Well there ya go. Rewired the plug AGAIN checked continuity, good, plugged it in and turned on the three way switch and hazards and voila! Lights! Almost! Haha! Looks like I have a couple taillights that need replaced.

Thanks for the help though street rod! I was freaking worried it was going to be something major and I couldn't think where to begin. All is good now!

Cheers!
 












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