junk4785@gmail.com

Newbie here! My 2020 Express 3500 6.0L Pass Van has a factory wiring harness pinned to the frame in the rear of the van. Does it have a brake controller, or will I need to add one? If so, I would greatly appreciate suggestions.
I will be picking up a travel trailer this month! I had to put on a tow hitch already.
For some reason I can't add a photo of my hitch pin!

tech2

if it didn't have a hitch it won't have a controller. did it have a 4 wire blunt cut or 7 wire blunt cut harness?
the oem factory controller has integrated sway control and fits out of the way...so it a better option but double the price. call your gm dealer to see if its an option they can add. if it can't be added then an aftermarket controller can be hardwired in.
i like tenkonsha controllers for aftermarket

junk4785@gmail.com

This is what’s pinned to the frame.

LWright

Just went through this myself and discovered to my great disappointment, that that “harness” pinned in the back isn’t for towing …supposedly for a sensor of some sort. Had to wire everything from scratch. Also, the four wires for the brake controller were available up front, but not connected to anything. Also, doesn’t have fuse connectors in the fuse box. Had to wire everything for the controller from scratch also …used a fuse tap to the brakes to get the signal needed. Put in the Tekonsha P3 controller that I already had.

junk4785@gmail.com

oh no! That’s stressful and expensive. Is yours a 3500 LT?

Michael Rodriguez

Same here. It would have been so easy for them to have everything ready to upgrade to the towing package, but they didn't.

I ended up installing my own breakers under the hood and running wires to the back for that. The tail light and blinker setup was pretty easy and there are a bunch of cost effective harnesses available.

Etrailer.com has several videos on how to do this. I used

the method with a fuse expander right from the fuse box. Their latest video shows where do t-tap into the break signal.

The whole process wasn't that hard. The frustrating part is that they could and should have had all the stuff to just make this an easy plug and Play install.

mountainmanjoe

Hey that's an interesting distribution block. Do you have a product link for that?

cjm1973

Unless they added an factory option for a brake controller over the last 2 years, I don't believe GM offers a built in FBC for it's heavy duty vans. I could be wrong but it's not an available option even if I custom order one of GMC/Chevy's build site.