How to Test Trailer Socket to Confirm Presence of Correct Brake Controller Signals

Published 10/14/2016

Products Featured in This Question

Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional

(2763)

$159.00

Hook Probe Circuit Tester

(60)

$12.27

Question:

i checked the controler it output is good on all the wires how can i check the plug , if i press the brake will i get a reading at the plug on the brake wire in the plug

asked by: Dave B

Expert Reply:

On your Prodigy P2 Trailer Brake Controller # 90885 the trailer brake output signal is carried on the blue wire only. The other wires are ground (white), 12V input power (black) and brake switch input signal (red). You can certainly check that the brake signal from the blue wire is making it all the way back to the vehicle's 7-way.

If you refer to the linked photo that shows a typical RV-style 7-way vehicle socket, you'll note that the usual wiring configuration has the trailer brake circuit carried on the pin at the 5-o-clock position (as you look at the socket). On this pin you should be able to apply a circut tester like # PTW2993 to detect a brake signal while a helper sits in the vehicle and applies the manual override lever. What reading you get will be a function of the power and boost levels you have selected on the controller. At full power you should read a signal in the range of 12 volts. Please see the linked video on using a tester.

The two linked article may be helpful to you as you test.

expert reply by: Adam R