Weak Brakes on Multiple Trailers with Same Tow Vehicle

Question:

My tow vehicle is a 2001 GMC Sierra 2500 with a prodigy p2 controller. Im experiencing weak brakes on multiple trailers with them turned all the way up and using the manual lever.I have pulled the trailers with another truck and everything works fine. I have tested the output at the connection and and getting 11.4 volts with the manual lever pressed and turned all the way up. I tested with a test light and everything appears to operate as it should. Any ideas on what the problem may be?

asked by: John

Helpful Expert Reply:

The issue that you presented points to signs of a short on the brake output wire (usually blue) that runs from the brake controller all the way back to the 7-way trailer connector. My question to you would be where you tested the wire at and got 11.4 volts? If it was directly behind the brake controller then that means the brake controller is in working order.

However, the remaining part of the brake output wire that runs from the brake controller all the way back to the 7-way trailer connector could be shorted out and what is causing weak braking power. In order to test this you are going to want to obtain a multimeter and then test the pin in the 5 o'clock position on the vehicle side 7-way with the controller turned all the way up and while the manual override is applied. You should be getting very close to 12 volts here and if you are not it is because there is a short on this wire and it will need to be repaired or replaced with 10-1-1 (per foot).

Please let me know once the above has been completed and if the issue is resolved or not.

expert reply by: Conner L