Why Would Brake Output Circuit Have Low Voltage When Not Connected to Controller

Question:

2005 silverado 2500 hd, tekonesha prodigy 2 controller, single harness from controller to factory trailer brake connection under dash. The issue is the test light shows dim illumination on blue wire at the 7 way connector and at the factory plugin even when the blue wire is severed from the controller. i am assuming this is a short in the truck wiring and not a brake controller problem. Am i correct in my thinking? Thank you for the help.

asked by: David H

Expert Reply:

Yes you are correct. You have a short between the brake output circuit and most likely the 12 volt accessory circuit since the test light is partially lit all the time. Most likely this is due to corrosion on the 7-way. Check out the back and inside of the connectors looking for any corrosion or exposed wire and fix as needed.

expert reply by: Jameson C