While wiring up a new plug in the bed of my 2005 2500 for the 5th wheel to plug into I find the wire sizes coming from the dash of the truck is very small compared to the wire size in the drop cord from the trailer. It looks like Dodge uses 12 and 14 guage wires all the way from the dash!! The trailer cord has large guage wires. All look to be 10 guage or so. Doesn't this cause a voltage drop especially in the brake and ground lines???

 

On my 03 they are actually #14 and 16, pure cheap out. They get around it by using the free air rating of the wire size, and save themselves $5 per truck. The voltage drop isn't actually an issue but you could replace them if it makes you feel better.

 

I contacted the brake controller manufacturer and told them about my observation about wire size when considering the leads they supply coming from the controller and the wire size in the drop cord from the trailer. The guy immediately ask me if my vehicle was a Dodge!!! He said they had calls very often from people on this. He suggested I run quality 12ga or even 10 ga wires from the controller for the brakes. I did.