Tekonsha Prodigy Brake Controller Shows SH and OL Codes

Updated 06/06/2012 | Published 06/05/2012

Question:

I just replaced the 7 pin connector on the trailer wire. When its plugged in and the truck is on, the prodigy brake controller flashes SH every second and then when the brakes are applied it flashes an oL code. Some of the time it shows .c. and others it flashes .nc. On top of that, it shows the percent of power it supplies to the brakes and then back to SH. All this happens in about 10-15 seconds.

asked by: Brian

Expert Reply:

The SH code is indicating a short circuit and the OL is indicating an overload situation. You will want to check the trailer connecter that you replaced and make sure that it is wired like in the picture I have provided.

Also check the vehicle side connector for any dirt or corrosion in or behind the connector that can be causing the short and overload issues.

The .c. means that a trailer is connected, and you have the boost on, while the .nc indicates no trailer connected. You have a short somewhere that needs to be addressed.

Disconnect the trailer and test the brake controller by itself. Sever the blue wire a few inches back from the controller. Use a circuit tester like # PTW2993 to test the end coming out the controller while fully applying the manual override. If it works properly, then you know the issue is not the controller. If the blue wire shows power all of the time or is erratic, then there is something wrong in the brake controller and it will need to be replaced.

You will also want to check the trailer wiring to see if there are any nicks in the wiring touching the trailer frame that can be causing the short. Make sure all grounds are attached to clean bare metal surfaces. You can also check the brake magnets by following the FAQ I have linked.

expert reply by: Michael H