Blue Wire Showing Voltage with No Trailer Connected and When Not Applying Brakes on Brake Controller
Products Featured in This Question
Question:
My brake controller light does not illuminate when I have the brake controller installed with confirmed + voltage to the black wire and confirmed ground to the white wire. Should that light be red if the trailer is not hooked up? Also, the blue wire is showing positive voltage without the brake pedal being depressed. When I test that wire for voltage, the light on the controller lights up green, indicating that the trailer is hooked up even though it isnt. Should that blue wire have constant voltage the #2 pin also has constant voltage at the tow vehicles 7-pin connector? Should the red light be on if there is no trailer hooked up and power supplied to the controller? Not sure what this part #5100 is. I have a Voyager Tokensha brake controller
asked by: Bradley W
Expert Reply:
It does sound like there is a short to the brake controller through the wiring or in the internal circuitry of the brake controller. Since your brake controller shows no red light this indicates a short to the brake line (blue wire).
If you are using wiring harness, # 3040-P, make sure that extra white ground wire is attached to a clean bare metal surface. If it is hardwired to the truck, the ground needs to be connected to the negative battery terminal.
Sever the blue wire a few inches back from the controller and use your circuit tester to test the wire. If it shows voltage without applying the manual override, then this indicates a problem inside the controller and it will need to be replaced. If the issue stops, there is a wiring problem somewhere between the controller and 7-Way.
The controller will send a small amount of power back to check to see if a trailer is connected but it should be just a tiny amount. Applying a circuit tester to the wire could trick it into thinking there is a trailer connected because it adds more of a load on the system.
You would need to check to make sure the wiring is intact on the harness and on your truck including the grounds. If you cannot find a wiring or ground issue, then something is wrong with the internal components of the brake controller and it will need to be replaced as there are no internal serviceable parts.

Product Page this Question was Asked From
Tekonsha Voyager Trailer Brake Controller - 1 to 4 Axles - Proportional
- Trailer Brake Controller
- Proportional Controller
- Electric
- Splice-In
- Under-Dash Box
- Under-Dash
- Up to 4 Axles
- Indicator Lights
- Single Trailer Only
- Tekonsha
more information >
Featured Help Information
Instructions
Continue Researching
- Shop: Brake Controller
- Shop: Trailer Hitch
- Shop: Trailer Wiring
- Q&A: How to Install a Brake Controller on a 2014 Ram 1500
- Article: Brake Controller Installation: Starting from Scratch
- Search Results: etbc7
- Search Results: tekonsha 118784
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Article: Towing a Trailer? Let's Talk About Brake Controllers
- Search Results: curt
- Article: Which RV Propane Tank Size Do I Need?
- Video: 2009 Chevrolet Silverado etrailer Trailer Hitch Receiver: Complete Installation
- Video: Set up: Curt TriFlex NEXT Trailer Brake Controller on a 2021 Jeep Cherokee
- Shop: Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 7-Way Trailer Connector
- Shop: Tekonsha BRAKE-EVN Trailer Brake Controller w/ Custom Harness - 1 to 4 Axles - Proportional
- Video: What to Know About the Curt TriFlex NEXT Trailer Brake Controller
- Q&A: How to Install a Trailer Brake Controller on a 2009 Chevy Silverado
- Q&A: Replacing OEM Trailer Hitch on 2009 Chevy Silverado 1500 Z71 with Draw-Tite # 75521
- Shop: etrailer Trailer Hitch Receiver - Custom Fit - Matte Black Finish - Class III - 2"
- Video: Curt Discovery NEXT Trailer Brake Controller w/ Custom Harness: The Breakdown
- Video: Best 2022 Hyundai Palisade Trailer Wiring Options
- Video: Curt Venturer NEXT Trailer Brake Controller w/ Custom Harness Feature Review
- Video: Set up: Curt T-Connector Vehicle Wiring Harness for Factory Tow Package on a 2022 Hyundai Palisade
- Shop: Trailer Axle w/ Electric Brakes - Easy Grease - 5 on 4-1/2 Bolt Pattern - 95" Long - 3,500 lbs
- Shop: etrailer Electric Trailer Brakes - 10" - Left/Right Hand Assemblies - 3,500 lbs
- Shop: Curt Trailer Hitch Receiver - Custom Fit - Class III - 2"
- Shop: Curt TriFlex NEXT Trailer Brake Controller w/ Custom Harness - 1 to 4 Axles - Proportional
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Search Results: weight distribution hitch
- Q&A: How Much Voltage Should Be Applied To Brakes on Trailer w/ Electric Brake Controller