Troubleshooting Blue Brake Control Wire on Factory 7 Way Connector on 2018 Ford F-150

Question:

A trailer repair expert says maybe my trucks trailer plugin meaning the blue wire is not powering the bypass solenoid for my surge brakes how can I verify this

asked by: Steve K

Expert Reply:

It sounds like you're having some trouble with the brakes on your boat trailer and the trailer repair person who looked at your trailer says the issue isn't on the trailer, that it is instead on the vehicle. He seems to think that it's all tied into the brake controller wire (usually blue) on your truck's 7 way connector.

If that is the case, let's start by testing the 7 way on your truck with a circuit tester like the # PTW2992; you'll want to test the pin at the 5 o'clock position on the 7 way connector (check the attached picture for the Blue (Brake Control wire). To do this, you'll need a friend to activate the manual override on your brake controller or press the brake pedal to verify that that circuit is receiving power when they do this. If you're not getting power at the pin, you'll want to test the wire behind the connector using the same procedure. If you don't receive any power on this wire, then you'll need to trace it back as far as possible looking for damage to the wire and replace as needed. If the wire gets power but the plug does not, you'll want to replace your 7 way using the Hopkins # HM40975, which you'll just plug into the back side using the US Car Connector that you remove from the old plug.

I've attached one of our helpful articles on 7 way wiring that you may want to reference back to when you're first starting this troubleshooting process up. If the steps I've mentioned above don't correct the problem, please let me know and I'll continue to work through this with you.

expert reply by: Erik B