Question Was Asked By - Gene D

Can I Check P3 90195 Brake Controller With a Voltmeter at the 7-Way

Question:

I have a Tekonsha P3 brake controller. Is there a way to check the brakes with a voltage meter or must the vehicle/trailer be moving slowing down? I assume volts/amps would be increased when brakes are applied, when moving. I can see some voltage at the 7 pin plug when the auto is not moving but this does not prove much.

asked by: Gene D

Expert Reply:

Yes, you can sue a circuit tester to check the function of the brake controller at the 7-Way. You will see some voltage at the 7-Way on the brake controller pin when the controller is on. It sends a small amount of current, not even enough to engage the brakes, all the time. This current is used by the brake controller to detect whether or not a trailer is connected.

When you shut your truck off, after a period of inactivity, the brake controller will shut off and no longer send this test current.

expert reply by: Patrick B

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