Great site. new member here, first question. I have an '01 supercrew 2wd and i just bought a new boat. The trailer has a 5flat plug and my truck came with a 4flat plug, I bought a 5flat wire harness but I don't know how to wire it correctly. Thanks, any help or advice on what to do.....

 

The 5-way can be wired multiple ways...it's kinda an oddity in the trailer industry.

It is like a standard 4 pin as far as wiring color and wire placement.....plus an extra.

Trailer-----Function--------Truck Color

White-----Ground----------White
Brown-----Running Lights---Brown w/ white trace
Yellow----Left Turn/Stop---Yellow
Green----Right Turn/Stop---Green

Now for the extra.
It should be black or red on the trailer and can either be a auxillery 12v or a reverse to lock off the brakes when backing.

Reverse on the truck is brown with a green trace and Auxillery on the truck is orange.

The wire you won't use is blue...it for electric trailer brakes and requires an electronic brake controller in the truck to function.

I hope this helps.....

 

Thanks Colorado, However, the plug is a product made by "Wesbar" 5flat.
the color code is as folows;

white
brown w/yellow stripe
yellow
green
blue

The white wire has a silver nipple male lead at the base of the rubber end.
the rest are female type.

What do and where do i remove the existing 4flat plug in order to install the new 5 flat plug and which wires go to where?

 

The white is the ground and goes to white

Brown goes to brown w/ a yellow trace
yellow goes to yellow
Green goes to green

Traditionally a blue wire is electric brakes, but most boat trailers do not have electric brakes. You need to find out where that wire goes on the trailer. If it goes a surge master cylinder it will be the reverse lock out and needs to be connected to the brown with the green trace. If it goes to a battery for charging or on-board boat charging it will connect to the orange wire.

If the trailer truely has electric brakes it will connect to the blue wire.

As far a what to do with the existing 4-pin, leave it alone and tap into the tires behind that feed it.

 

Thanks Colorado. Fellow brother, i can't thank you enough for the info. You are the truely one of the great ones' You are right about the fact that the trailer has a surge brake system. I will use the 5 flat blue wire to tie into the that. Another question (if you don't mind) This is my frist time towing a boat, my truck did not come with a tow package, should i think about installing a trans oil cooler and if so which one you you recommend, Also what other mods do you think i should look into on prepairing my truck for towing. Once again, Thanks

 

boat size/weight?
single/double axle trailer?

Most single axle trailers with a boat will need no additional trailer type stuff for the truck.
Seeing as it has surge brakes I would say that it is probably a double axle trailer meaning trailer/boat combination weight is probably between 4500-7000lbs....but could be as high as 13,000lbs. The Vin tag on the trailer will give you axle capacities...most likely 3500lb ea. or a trailer total capacity of 7000 GVW.

If it is a triple axle trailer your weight is probably between 14,000 and 20,000lbs.

Another factor is how much and how far you tow. If you only tow a 5k load once a month 20 miles each way, I wouldn't upgrade the truck at all. If that same load is towed daily or a couple times a week I would upgrade the trans cooler. If the tow weight goes above 5k and you tow it with any regularity I would recommend upgrading the trans cooler also.

 

If your trailer has surge brakes, does it have surge activated DISC brakes? The blue wire in this type of system needs to be hooked to the reverse light circuit in your tow vehicle. The reason for this is that with a surge brake system, when you slow down or stop, the coupler at the front of your trailer compresses a small master cylinder which activates your brakes. (The brakes are generally either drum or disc.) When you back up, the same thing happens and your brakes end up getting applied.

The big difference is that discs are more efficient than drums, so when you try to back up with them, they lock right up. So, to counteract this, they add a solenoid that literally blocks the brake line - but only when you back up. How does it know you're backing up and not stopping? It's triggered through the blue wire by your reverse lights.