Troubleshooting Activator Brake Controller that Displays Overload Message

Updated 03/10/2015 | Published 03/09/2015

Question:

What dose it mean when trailer is plunged in and truck running when I step on brake pedal the controller says OL on the screen

asked by: Jim B

Expert Reply:

If the Draw-Tite Activator IV Trailer Brake Controller # 5504 is displaying an OL (overload) error message that means there is a short somewhere on the brake output circuit on either the truck or the trailer.

Start by examining the trailer connector. Make sure that the pins on the vehicle side of the connection and the sockets on the trailer side are not damaged or corroded. If you can see green corrosion on the pins or the sockets, there is a possibility that the corrosion may have spread to the interior of the connector itself, causing a short.

Trace the output circuit back from the connector to the trailer brake magnets. Check the brake output wire (usually a blue wire) for pinch points or worn or cracked insulation. If at any point in the circuit there is copper conductor showing, it can possibly short out on the trailer frame. You will also want to examine your brake magnets and their connections.

Make sure that the ground connection for each magnet is securely attached to the trailer frame. Check that the brake magnets are not excessively worn. If you pull the brake drum off and can see the copper windings through the face of the magnet, it is time to replace them.

expert reply by: Jameson C