The heavy Orange Wire in the trailer brake harness, where does it go? What was it for? There are three wires going to the plug near the drivers side rear. The heavy blue trailer brake wire is one, but I cannot figure out the function of the other two.

Thanks in Advance,

Aaron

 

From the external light(s) diagram ...

Orange - Battery Charge
Yellow - Left Turn Lamp
DK GRN #1 - Right Turn Lamp
White - Trailer Ground
Blk/LTGRN - Backup Lamps
Brn/White - Marker Lamps
DK GRN #2 - Electric Brakes

 

Yep, Jim's got it right.
Here's a good link
How to Wire your Car or Truck for Trailer Lights

 

Yep , that orange wire is a charge line for an auxiliary battery either in a trailer or slide in camper. It's isolated from your main batteries by a relay that only allows current to flow when the engine is running, this prevents your aux battery from drawing from the main batteries and killing them.

 

Thanks everyone. I went ahead and wired my trailer receptacle with the information provided. I do have anther question however. Where is the trailer battery recharge relay? I cannot find it for the life of me. There are four under the hood but none are listed as such. The 30 amp maxi fuse is good. The small fuse in the cab that feeds the relay is good, but the relay is no where to be found. I also have no power on my reverse light wire. I connected it into the plug, but it has no juice when the key is on and in reverse...

Thanks in Advance,

Aaron

 

there are two relays outside of the underhood box fuse, is one of them

 

BTW the other is for trailer back up lights

 

On the front, back, side? I am looking for a connection for these relays. I found two gray connections behind the box down by the PCM, but these do not look like relay connections. I will keep looking.

Aaron

 

If your truck had a trailer tow package it would have a small box with the trailer battery charge relay and trailer back up light relay attached to the back of the main underhood fuse box.

Mine didn't have one either so I just used a bosch relay and mounted it to the fender. My trailers don't have reverse lights so I just used 1 relay for the charge line.

 

Thanks everyone. I finally figured it out. It turns out that I have all the wiring and fuses, but no relays. Gonna do as Blue Mule suggestted and put a relay in for the charge wire...

Might just hard wire it to get through next week.

Aaron