Trailer Brakes only Work When the Manual Override Lever is Activated on a P2 Brake Controller

Question:

HEY BOB, I CHECKED THE RED WIRE ON THE COLD SIDE OF THE BRAKE SWITCH AND IT WAS CORRECT. I GOT POWER WHEN PUSHING ON THE BRAKE AND NO POWER WHEN I LET OFF THE BRAKE. THE CONNECTORS ON THE WIRE HARNESS AND THE BACK OF THE PRODIGY LOOK GOOD AS THEY ARE BOTH BRAND NEW (PRODIGY AND DELUXE INSTALL KIT WAS PURCHASED AT ETRAILER) AND INSTALLED BY MYSELF. THE PRODIGY IS MOUNTED AT 90 DEGREES ON MY 2000 TOYOTA TUNDRA. HOPEFULLY NOT BUT WAS WONDERING IF THERE IS A "TEST" THAT CAN BE PERFORMED OR WILL I NEED TO SEND THE PRODIGY BACK TO ETRAILER. WILL APPRECIATE ANY HELP. WANTED TO GO CAMPING THIS WEEKEND.

asked by: DAVID

Expert Reply:

It sounds like the P2, item # 90885, is not properly connected to the vehicle stop light switch. Since the brake controller has power and the trailer brakes work properly when the manual lever is activated, the black, blue, and white wires are connected correctly.

You will need to connect the red wire from the P2 brake controller to the cold side of the stop light switch. Use a circuit tester, item # PTW2993 if needed, and find the wire at the brake switch that has power only when the brake pedal is pressed. Connect the red wire to this circuit.

The "c" in the display of the P2 indicates that you have the boost feature engaged on the controller. If you press the boost button momentarily the display will show which setting is engaged. The boost setting can be changed or turned off by continuing to press the boost button. When the boost feature is off .c will be displayed.

expert reply by: Robert G

David

9/8/2010

Bob G.

9/8/2010

If you have the Prodigy brake controller, the mounting position is the issue. The Prodigy can only be mounted up to a 70 degree range (see instructions link). If you have it mounted at 90 degrees the accelerometer will not function properly and when stopping with the brake applied the trailer brakes will not activate. You will need to change the mounting position so that the brake controller can be mounted inline with the direction of the vehicle travel, and in no more than a 70 degree up or down orientation. If you have the Prodigy P2, item # 90885, brake controller it should operate properly as long as it is mounted level Side to side in the vehicle in the direction of the vehicle travel. This controller can be mounted 360 degrees so a 90 degree mounting position is not a problem. There is a test that can be performed. The results of the test are dependent on the brake controller being installed and oriented properly on the vehicle. Sever the blue wire exiting the back of the controller. Leave enough wire to reattach the wire once the testing is done. Make sure the trailer wiring is not connected to the vehicle. Now, test the blue output wire with a circuit tester, item # PTW2993 if needed. You should get power when the manual output is activated. If not check the black power wire going into the back of the controller for 12-volt power. Next, check the blue wire for power when the brake pedal is pressed. You should show power on the blue wire when the pedal is pressed. If you do not have power, either the brake controller is mounted incorrectly or the red wire is not connected to the proper circuit. From the information you sent it sounds as if you need to change the mounting angle of the brake controller and everything will then work. If you get the brake controller mounted properly and perform all of the testing above, and the brake controller still does not operate properly, the controller will need to be replaced.