Trailer Wiring Question......

[SandyRiverRon]

Bought new tow rig, 01 Expiditon, trailer has flat 4, truck has 6 pin factory plug. I bought an adaptor from Ford to match the 4 and 6 but all I get is running lights, no brake or turn.....answers appreciated.

[fuzzy]

basics of 4 wire trailer
one wire (black) is ground
one wire (brown) is tail lights
one wire (green) is?left or rite
one wire (yellow) is left or rite
i forget without actually looking green versus yellow as far as righty / lefty
but the brake light and the turn signal are on the same filiment of the bulb and the tail light is the lesser bright filiment
if that makes any sense?

[Starfish]

This may sound silly but did you check for fuses in the trailer tow fuse locations? That rig has separate circuits for trailer tow lights, stop/turn besides the ones for the truck itself. In other words the taillights on the truck can work without having power to the trailer harness.

FYI, if you try wiring a fifth wire (backup lights or brake cutout) you'll also need to add a relay in the empty slot provided for trailer back-up lights.

[PRINCEMASTER]

Unfortunately with the newer vehicles you need to purchase a conversion box. It plugs into the factory harness under the back of the suv inline to the wiring and has a plug on it for the trailer. You can get them at any trailer shop or the factory. Come to think of it schucks may even carry them. :yay:

[Troller]

Hi, I have never seen black as ground on any of my boat trailers. It is commonly ground in dc circuits but I believe they use white as the ground. Someone correct me if I am wrong but I am pretty sure both of the boats at home are using white as the ground.

My question to you have you ever used the trailer plug on anything else or do you have something that you can plug it into to check and make sure the 6 prong plug is working. That way you can eliminate the adapter you just purchased. If you have a volt meter you can also check it that way.

[SandyRiverRon]

Haven't checked the plug yet but since I had running lights I figured it was working (to a point), thanks to everyone for the ideas.

[HntnFsh]

White is the ground.Make sure you put it in a good clean bare metal spot.I bought an adapter at Wally world yesterday.Has 4 wire falt on 1 side the 6 round plug is next to it.You just plug in your original 4 wire flat to the back and attach the ground.$24.95 its a Hoppy product.Easy to mount and gives you both options.Has the red and blue wires for aux.and trailer brakes.I realize this is thw opposite of what your looking for but you should be able to find 1 that connects with the 6 round.Their website is www.trailerwiring.com (http://www.trailerwiring.com)

[garyk]

S-R-R,

As you'll see in my post about a short-circuit I had several concurrent problems that were confusing to sort out.

The last problem... I was exactly where you are: adapting a 6round to 4flat, and having only taillights - no turn signals.

What was really confusing was when I attached that adapter to the truck and checked the output with a simple continuity tester, everything was fine. Then plug the trailer into the output and no taillights! What's going on here!!??

I finally deduced that even though the adapter looked clean, it wasn't clean enough, the trailer plug must not be making good enough contact.

So I cleaned up the adapters output side (female terminals) with a Dremel tool and emery papers and PRESTO, working lights!

[Boatdog]

Garyk,

Was that short 'in the plug' as you guessed?

[Beancounter]

Here's what u need http://shop.easternmarine.com/index.cfm?fuseaction=catalog.prodInfo&productID=54 02&categoryID=210.