I have a 2001 Silverado, i'm picking a new travel trailer in a few days. My truck has the basic trailer wiring harness going to the back of the truck, 6 wires, which is wired to a 7 pin plug. I need to have the red and dark blues wires for battery and electric brakes, what do i do, do i replace the complete harness, or run an extra 2 wires?

 

if this is the factory plug and hitch at the back the 12 volt lead is already there ,but you may have to activate the circuit with a 40 amp maxi fuse .the brake wire is there also just install a brake control with the correct tap plug and you should be ready to go .here is a little page or two with pictures to help .http://www.etrailer.com/faq_cbc.aspx