Troubleshooting Draw-Tite Activator II Brake Controller That Displays OL Light

Updated 10/12/2015 | Published 10/11/2015

Products Featured in This Question

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

(2763)

$159.97

Hook Probe Circuit Tester

(60)

$12.41

Question:

Have a 2011 Silverado the activator ll came out of my 06 Silverado. I have a 03 Silverado that has a trailer brake system on it and it works fine. When i activate the system on the 2011 the ol light comes on but if you mess with it it will give you the # readings but will not stay on long enough to activate trailer brakes. Now my ? Is is it possible that the unit itself has a short in it. Thanks.

asked by: Mark

Helpful Expert Reply:

The Draw-Tite Activator II Brake Controller 5500 will display the OL (overload) message when a trailer is connected if it senses a short or overload in the trailer's brake circuit. If it displays this message without a trailer connected this means that there is a short somewhere in the truck's brake circuit wiring.

Since your Activator II is shutting down after a few seconds it does sound like there could be internal damage to the unit. You can test the controller (without a trailer connected) by cutting the blue wire a few inches from the controller (leaving enough slack to re-connect it) and by testing the wire from the controller with a circuit tester like # PTW2993. Press the brake or manual override and see if an output signal appears on the blue wire. If there is a signal coming out of the unit then the issue may be in the truck's wiring for the brake circuit. Trace the blue wire back to the 7-way looking for worn or cracked insulation, especially around spots where that wire has to bend and where it may touch the trailer frame.

If there is no signal coming out of the controller, next test the red wire which carries the brake light switch input signal to the controller. Press the brake and test the red wire; if there is no signal reaching the unit this could mean a faulty connection to the switch. If there IS a signal going in but not coming out then the unit is damaged and should be replaced with a unit like the Prodigy P2 # 90885 which is highly-rated by our customers for its reliability and easy set-up.

expert reply by: Adam R