2000 XLT towing hookup issue

[Whitfield]

I ordered the plug for the tow plug on my explorer online the other day so I could take my son fishing today on my day off. (The stock plug on my truck is round and has 4 connections in it) It plugs into my truck with no problem and my trailer (old plug). Only some of the lights worked. I used a tester and confirmed that I do have good power coming from each of the four connections on the truck side so it must be the lights on my trailer. The ground is good - cleaned with a wire brush and re-did it.

Didn't really like the lights on the trailer so I went to the store and purchased a nice new set of LED lights. Problem is I didn't realize when I purchased them that they are a five flat and my truck is a four flat. Since four of the five wires were the correct color I went ahead and replaced the harness and hooked it up as correctly as possible and then wired a five flat connector to a four flat connector so it would plug into my truck. Still not getting anything on the drivers side of the trailer and the ground is good.???

For the extra blue wire on the lights, I did connect it between the two lights but it is not connected to the truck (yet). Could this be my problem. I did not plan on connecting the reverse lights until I could get the correct plug. Can I ground this plug out and possibly that would work? I didn't want to try grounding it without asking because I am not lucky when it comes to things like this. It would seem since this plug is for the reverse lights it would need to go to power. Could I hook to another power lead such as brakes and have it work this way?? Thoughts please? I hate wiring LOL Tks

 

[J_C]

I do not know how your LED lights are wired. I do have a scan of the factory tow wire harness that came with my '98. It lists:

A) Dark Green - Trailer RH Turn Signal - Relay controlled, activated when brake pedal depressed or when ignition on and RH turn signal applied.

B) Yellow - Trailer LH Turn Signal - Relay controlled, activated when brake pedal depressed or when ignition on and LH turn signal applied.

C) Tan/White - Tail Lamp - Relay controlled, activated when Park/Head Lamps are on.

D) White - Ground

A blue wire on a 5 way plug is usually (is standard) for trailer brake control. I don't see a reason to connect it between the two lights and would disconnect that. It might help if you can link to the light set you bought and/or provide more info about it. Maybe they got the color wrong (should have been purple for reverse lights). I take it your LED light set does have reverse light(s)?

If so then it seems like it *needs* to use the blue wire for that, except that without it coming from the vehicle, you would have to tap into the main backup light circuit to make that work and add an additional connector or replace the 4 pin. However, the standard I'm aware of uses a 7 pin for adding backup lights so to alter either and use the 5th pin for reverse, means the truck and trailer are forever married to each other, will not work with anything else as any other vehicle with 5th wire, would cause the trailer reverse lights to come on when the brake pedal is pressed. I may be barking up the wrong tree, should have asked for more info first.

If I understand correctly you are getting 12V on the Yellow wire when brakes are applied, and 12V on tan/white when parking/head lamps are on. I would then see if the individual LED lights can be disassembled to some extent to measure for continuity (very low resistance) between their positive wire contact and the trailer plug, although when I wrote "very low" resistance, it is possible it is a budgetized design that intentionally puts a resistor in series somewhere to limit LED current, or a high end set might even have an LED driver circuit so not a direct measurable path from LED to harness connector. More details about what product you have might allow determining this.

 

[Whitfield]

Thank you, that was very helpful. I finally got it.

The blue wire was connected in the package so the light could be tested in store so I connected it. Then I adapted a four flat / to five flat using only four wires then I tapped into the truck lights with an extra wire and tapped the reverse light lead so now I have reverse lights on the trailer. I put this on a single wire plug and taped it to the four flat connector. It was quite helpful this evening backing the boat back in to place in the dark. You know I had to take the boat out, if only to see what the new lights looked like at night. Fishing wasn't to bad either.

Thanks again for all your help.