Troubleshooting OL Code on the Draw-Tite Activator IV Brake Controller

Updated 10/18/2012 | Published 10/17/2012

Question:

I intermitently get a OL code and my trailer brakes are not working. It will work properly if I set the amp below 2.0, but if I go any higher, it will OL on me and not send voltage to my brakes?

asked by: Brian

Expert Reply:

The OL code on the Draw-Tite Activator IV Brake Controller, # 5504, indicates a short on the brake controller output circuit somewhere between the brake controller and the brake assemblies on the trailer. This is the blue wire coming from the brake controller.

A common situation that causes this is a damaged or corroded trailer connector. Carefully examine the metal pins on the trailer plug and vehicle socket for corrosion. It is possible that the corrosion might have spread to the interior of the connector where the wire actually attaches to the terminal on the connector itself. The corrosion can prevent the voltage from passing through the connection or cause the circuit to come into contact with an adjacent terminal, causing a short.

If you inspect the connectors and determine they are not the cause of the issue, then I would recommend using a circuit tester, item # 3808 if you do not have one, to test the pins on the socket for proper function. Find the pin for the brake controller output, it should be the pin in the 5 o clock position. Have someone step on the brakes or press the manual override and see if voltage is reaching the vehicle connector when set at full power. If you do have power at the vehicle socket, then we know the issue is on the trailer. If you do not have a signal, then the issue may be on the vehicle. I would recommend inspecting the brake output circuit on the vehicle for any pinched, frayed or damaged sections that could cause a short.

If the issue seems to be on the trailer, then trace the blue wire that carries the brake voltage from the trailer connector to the brake magnets. Make sure there are no loose connections, pinched or broken wires. Look for wire insulation that is worn or cracked. If the copper wire has been exposed and allowed to contact the trailer frame, a short is likely.

If you cannot find a wiring problem then the problem may be that the brake magnets are worn out and they will need to be replaced. If you can see the copper windings in the magnets then they are in need of replacement. We have replacement magnets available (see link). I have also attached an article on how to test brake magnets and on trailer wiring that you may find helpful when inspecting the wiring on your trailer.

expert reply by: John H