Brake controller install issues

[afest]

Is your new brake switch bad? Power on that wire with brake switch disconnected?


View attachment 473055

View attachment 473056

I doubt the switch is bad but anything is possible, and yes I have 3.9 volts on the blue/white blunt cut wire all the time whether it’s plugged into the brake switch or not…. Only way to get it to go away is to pull the BCM fuse as previously mentioned. I can confirm after driving it just now that the cruise control still doesn’t work with new brake switch.

 

[mikez71]

Think you're right. j3-3 and it looks like the only path it takes.. Maybe that diode died...

 

[afest]

Think you're right. j3-3 and it looks like the only path it takes.. Maybe that diode died...

View attachment 473059

First of all, these schematics are incredible! How does one acquire these?
After seeing this I would say that’s more than likely the culprit. I’m going to print these off. Leaning towards ordering a new BCM from Highway 71 auto part as there in close in MN…
Thank you very much

 

[mikez71]

Light Duty Prior To 2013 - GM Upfitter

www.gmupfitter.com

You can search for 07 electrical instead of the 08 one I screenshotted.

Also different diagrams a charm.li

 

[Jetskier77]

I sure hope its not your BCM. I had to replace that a few years ago and it was over $800 by the time they programmed it.

 

[afest]

Well I finally got a new(used reflash) BCM installed. Seemed to fix my issues. I also installed another new brake controller from etrailer and that seems to be work correctly. Thanks to everyone’s help.