2011 Suburban Unknown Wire
 

Hi,

I just got a 2011 Suburban 4x4 5.3L with HD Tow Pkg. In poking around under the hood, there is a red wire with an eye type connector rolled up between the underhood fuse box and the fender, any ideas?

Welcome to the forum.

Not sure but I think it's if you hook up a trailer brake controller or maybe it's for the OEM brake controller that needs to be hooked up. If no one else knows for sure, ask your dealer's service mgr.

Thats exactly right, it is for the electronic brake controller. The other wire is for the charge line out to the pollack connector located under the rear bumber.

I'd double check
As I think the "red" is for the 12v for the trailer harness for a trailer battery, I think the trailer brake wire is located between the fuse box and fender well and is "blue"

I stand corrected, it is also red w/black stripe, I went out and looked at mine and its still bundled up and is red. The trailer battery wire is also red w/black stripe and is located below the brake booster...
I don't recall where the hell I got the blue from....:eek::p