bing tracking image
Q & A Icon

Trailer Brakes Not Working On A 2016 Chevrolet Silverado 3500


I have a 7-way plug 1 in bed and one in bumper. When pulling trailers I have no brakes. The fuse is good. Its a 2016, Lkz 3500 chevy diesel. Thanks


Helpful Expert Reply:

The first thing you will want to do is check the inside of both the vehicle's and trailer's connectors for debris or corrosion. If corrosion is present, you will then want to spray some electrical parts cleaner on the inside of the connectors to clear the debris.

The next thing you will want to do is test the 5 o'clock pin at the back of the vehicle's trailer connector to make sure it is receiving power when the manual override on the brake controller is activated, you will need to have a friend sit in the vehicle and perform this function as you are testing the connector in the rear. This will in turn allow you to determine if the truck is actually sending power to the trailers brakes.

If the signal is not being sent back to the trailer's brakes, you will first want to visually inspect the wires from the back of the vehicle's trailer connector to their location on the wiring harness. Once completed and if no damaged wires are found, you will then want to sever the blue brake signal wire about 6" back from the brake controller. Using a circuit tester like part # 40376, probe the end of the blue wire from the connector while applying the manual override on the brake controller. If the wire is not receiving power, the brake controller is likely bad and will need to be replaced. If the brake signal is leaving the controller but not reaching the trailer, you can run a new brake signal wire from the controller to the vehicle's 7-way connector using the 10 Gauge Primary Wire part # 10-1-1.

If you are receiving power to the brake signal wire at the vehicle's trailer connector while the manual override is engaged, the problem is more than likely on the trailer side. The first thing you will want to do is ensure all of the trailer brakes ground wires are securely attached to a bare metal surface on the trailers frame. You will then want to begin visually checking the brake signal wire from the trailer connector all the way back to the trailers brakes, ensuring that you are taping and securing all loose connections. If you cannot locate the problem on the wires, you can run a new circuit using the Jacketed 2 Wire (Brake Wire) part # 12-2-1 from the brakes to the trailer connector.

Before joining the trailer connectors back together, I recommend using a dab of Dielectric Grease for Electrical Connectors part # 11755 inside the trailer plug. If you still cannot correct the problem after these steps, please let me know and I would be glad to offer further advice.

helpful expert reply by:
Conner L

Products Referenced in This Question

Product Page this Question was Asked From

Follow up Questions

2016 GMC Sierra 1500No Signal to red wire on Curt Triflex when brakes applied.Is it possible to use third brake light wire as a signal to red wire.Where is the third brake wire under the dash? or is there a better solution?
Etrailer Expert
Reply from Jacob H.

There should be a factory plug up underneath the dash on the driver side. You and use # C51451 to connect the Curt Triflex directly to the factory wiring. It is a simple plug and play application.

Q & A Icon

Similar Expert Q&A Pages

See More Q&A Expert Answers >>