Brake Controller Display OL Overload Message When Brakes Are Applied

Updated 05/13/2015 | Published 05/11/2015

Products Featured in This Question

Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional

(2763)

$159.19

Hook Probe Circuit Tester

(60)

$12.27

Question:

Hello when I press on my brake pedal I keep getting a code flashing OL. I just recently put new brakes on my trailer and I cant figure out whats going on. Sometimes they will work other times they wont. Seems like when I have the setting on a lower voltage itll work but on a higher voltage it wont. My right rear brake was not getting power to it so I fuxed it thinking that would fix it but evendently not. Please help thsnks

asked by: Wade S

Expert Reply:

If your Draw-Tite Activator II Brake Controller displays an overload message (OL) when your trailer is connected this usually indicates a fault in the trailer's brake wiring. If the same message appears with the trailer disconnected, then this usually indicates that there is a short somewhere in the vehicle's brake circuit wiring.

You can use a tester like # PTW2993 to test the brake circuit's output at your vehicle's trailer socket. Disconnect the trailer and apply the grounded tester to the pin for the brake circuit (this is the pin at the 5-o-clock position in a typical 7-way installation - see linked photo please). Adjust the controller for maximum output level. You should detect a 12V signal on this pin when the manual override on the controller is pressed. If the controller behaves properly and generates the correct signal, then you can move on to the trailer. If not, then check the wiring from the trailer socket as far back as you can trace it looking for signs of damaged or exposed wire.

Inspect each brake assembly for any signs of cracks, wear or damage to the insulation of all wires. Look especially at points where the wires have to make sharp bends and where they may rub against the trailer frame. Vibration during driving can cause abrasion of the insulation and lead to a short. Also check the trailer wiring from the trailer connector all the way back to the individual brake assemblies. Repair or replace any damaged wiring.

Make sure your brakes' ground wires are solidly attached to a clean bare metal surface on the trailer. It does not matter which brake wire is used for ground and which for +12V but each ground wire must make full solid contact. You can try sanding off any primer or paint from the grounding point or relocate the ground to a new clean surface.

If you need a new controller I recommend the Prodigy P2 # 90885.

expert reply by: Adam R