Tekonsha P3 Trailer Brake Controller Shows Intermittent Overload Error Message

Updated 10/19/2020 | Published 07/30/2013

Question:

I have a 2007 Dodge Ram CTD and pull a 2013 Rockwood fifth wheel with 7 inch brakes. I have pulled this trailer with this controller for about 2000 miles with no issues. I have had the brakes set at about 7.4 and useing Power Boost setting #2 with very good performance. I have an exhaust brake so I seldom need to use the trailer/truck brakes for down hill braking so the brakes have had little abuse. Recently I started having an issue with an Overload No Brakes warning. This seems to happen more frequently the higher I have the power boost set as well as stop and go driving. If I apply the brakes with a lot of pressure I can feel the brakes apply and when the voltage gets to about 3 or 4 the warning will come on and I can feel the brakes disengage. The less pedel the less chance the warning will come on. I checked the votage/amps at the controller while setting still and it is reading about 7.8 - 8 voolts and around 4 amps. I checked the same at the 7 pin and it is reading about the same volts and about 5 amps. Does this seem to point to a magnet?

asked by: Jim

Helpful Expert Reply:

Based on what you are describing it would seem like the more voltage or the longer duration the brake pedal is used the more likely you are to get the error. This could be a short to ground, short on the blue wire, or a bad ground connection. It could also be a problem with a brake magnet or the trailer wiring.

To start troubleshooting first cut the blue wire a few inches back from the controller. Use you tester to test the end coming out of the controller. It should only show power when you apply the manual override. If it shows power at any other time then the controller is bad and will need to be replaced. If it checks out ok reattach the blue wire.

Next move on to the truck side connector. Check the trailer connector for dirt and corrosion. Also check where the wires attach at the back. Clean out any corrosion you find.

Moving on to the trailer you will need to check it for dirt and corrosion as well. Then make sure the main trailer connector ground is attached to a clean and corrosion free bare metal surface. Then inspect the wiring leading to the magnets. Check for breaks in the wires that might be touching bare metal. Do the same from the magnet ground wires and make sure they are attached to clean, corrosion free metal surfaces.

Next pull a hub and drum and inspect the brake magnets. If you can see the windings coming through then the magnets will need to be replaced. To further test the magnets you can follow the brake magnet testing FAQ article I have linked. I have also linked an FAQ article on troubleshooting brake controller installations.

expert reply by: Michael H

Carlos F.

4/30/2020

Hi there,So I cut the blue wire a few inches back from the p3 and now I get an error message saying, TRAILER NOT CONNECT?Im lost now. Is it possible my p3 is bad?

Chris R.

5/2/2020

The blue brake output wire is essentially the P3's connection with the trailer (when one is hooked up) - so the fact that you are getting that error message after cutting the wire isn't a problem. It will clear once you connect the wiring backup. With the wire still cut though, you will want to test it for power when applying the manual override on the P3. Make sure it ONLY gets power when you do this - if it doesn't, or if it gets power at any other time - then the controller is bad and needs to be replaced.