Brake issue!

[t18edwards]

My trailer brakes 2017 Z18 currently are not working. Checked the wiring harness (actually replaced connectors and plug). Checked the voltage and ground, all of my lights are working. Inside my truck on the dash, I get a message "not connected" on trailer brakes. Any help would be greatly appreciated.

 

[92 Nitro 190dc Owner]

I assume the same truck and the same trailer were connected and the brakes worked before now. The potential failure points (in no particular order) are the electric brake controller, the wiring to the truck trailer outlet, insufficient trailer ground, trailer wiring, or the trailer electric brakes. Here are the steps I would take to eliminate them one-by-one. Some of these you have already done. 1) check the trailer outlet on the truck (specifically the brake prong) for voltage (12v or a bit higher). Have someone apply and release the brakes in the truck while you are testing. The voltage should vary. If no voltage, it's either the wiring to the trailer outlet on the truck or if the voltage is constant, the truck's electric brake controller is defective. 2) If the truck's trailer outlet has voltage, you've eliminated any issue with the truck. So the issue must lie with the trailer. Connect the trailer plug to the truck outlet. Check the ground wire on the trailer to ensure the ground wire has no corrosion and is firmly attached to the trailer. 3) If the ground is OK, then check the brake wire on the trailer for voltage while the assistant depresses and releases the brake pedal. 3) If the trailer brake wire has voltage, you've eliminated the trailer wiring. The issue must then be with the electric brakes.

 

[DodgeBoy]

The brakes are not electric in any of these trailers, they are surge brakes. Unless you installed a electric over hydraulic system yourself. My Ram has a setting screen for the trailer brakes. You need to let the truck know that the trailer is a surge brake system. I don't understand why these trailers are using a seven pin harness when the four pin harness is all you need.

 

[92 Nitro 190dc Owner]

I made the assumption they were electric, based on the posting. Now I know for sure what assume means! Whoo boy!

 

[t18edwards]

I assume the same truck and the same trailer were connected and the brakes worked before now. The potential failure points (in no particular order) are the electric brake controller, the wiring to the truck trailer outlet, insufficient trailer ground, trailer wiring, or the trailer electric brakes. Here are the steps I would take to eliminate them one-by-one. Some of these you have already done. 1) check the trailer outlet on the truck (specifically the brake prong) for voltage (12v or a bit higher). Have someone apply and release the brakes in the truck while you are testing. The voltage should vary. If no voltage, it's either the wiring to the trailer outlet on the truck or if the voltage is constant, the truck's electric brake controller is defective. 2) If the truck's trailer outlet has voltage, you've eliminated any issue with the truck. So the issue must lie with the trailer. Connect the trailer plug to the truck outlet. Check the ground wire on the trailer to ensure the ground wire has no corrosion and is firmly attached to the trailer. 3) If the ground is OK, then check the brake wire on the trailer for voltage while the assistant depresses and releases the brake pedal. 3) If the trailer brake wire has voltage, you've eliminated the trailer wiring. The issue must then be with the electric brakes.

Thank you for the help.

 

[t18edwards]

The brakes are not electric in any of these trailers, they are surge brakes. Unless you installed a electric over hydraulic system yourself. My Ram has a setting screen for the trailer brakes. You need to let the truck know that the trailer is a surge brake system. I don't understand why these trailers are using a seven pin harness when the four pin harness is all you need.

I have a Ram, also. I will check the setting in my truck.

 

[JBoutfishn]

When truck is in reverse the surge brakes are locked out . Check to see if there is an issue in wiring that is allowing that lockout 12 volts getting to the trailer when not in reverse.

 

[Cyco]

When truck is in reverse the surge brakes are locked out . Check to see if there is an issue in wiring that is allowing that lockout 12 volts getting to the trailer when not in reverse.

Correct. Usually blue wire. When reverse lights are ingaged, it sends a signal to trailer to lock out brakes. Reverse lights working? Fuse???

 

[92 Nitro 190dc Owner]

Until you are able to diagnose the issue, you can always unplug the trailer or use a manual lockout.

 

[Ericvap]

The brakes are not electric in any of these trailers, they are surge brakes. Unless you installed a electric over hydraulic system yourself. My Ram has a setting screen for the trailer brakes. You need to let the truck know that the trailer is a surge brake system. I don't understand why these trailers are using a seven pin harness when the four pin harness is all you need.

The 5th wire is for the reverse locking solenoid. If you are backing up with surge/hydraulic brakes (In my case uphill into my garage) the harder the brakes apply/activate from weight pressing against the hitch, in turn the tow vehicle pushes harder against trailer brakes adding more braking to trailer brakes. The 5th wire reverse light signal blocks all fluid from pressurizing line/wheel brakes by using a solenoid inline behind master cylinder to keep all fluid inside master cylinder. I:E- no brakes to trailer and THAT is why it is a 7 pin connector!