BEDROCK

It seems I clutter the forum with strange questions too much but I've already contacted Tekonsha and Ford Service about this. I just installed a Tekonsha P3 brake controller on my 2012 F150. The P3 powers the brake lights when the manual lever is engaged but other than that it's not powering anything when not connected to a trailer. After installation, and not hooked to a trailer, engaging the manual lever would cause a heavy duty buzzing/humming sound in the back of the truck. This would only happen intermittently and has now stopped completely so I can't locate it while some one else runs the controller. Any one else experienced this?

kmac1036

Did you get all the fuses in? Which harness did you use? A plug and play one or the one ford leaves in the glovebox? The wire do not color coordinate. You have to follow the instructions that come with the brake and harness to make sure the wires are hooked up by function. You may have also blown a fuse by now.

BEDROCK

Plug n play harness. The unit still functions as it should. No blown fuses. I can duplicate the noise SOMETIMES when I step on the brake immediately after shutting off the truck. The harness must be powering something other than the lights.

kmac1036

When the trailer is hooked up and plugged in a hum when the brakes are applied is normal. My controller only lights up and works only when a trailer is plugged in. Make sure the power dial is turned all the way down when not in use. There may be a grounding issue. Will try to pull up the P3 docs when I get a chance.

kmac1036

re-read the original post again... if the trailer works fine & there's no error messages when hooked up you should be good to go. I had to add an extra fuse under the hood, my setup wasn't sending the 12v battery charge to the 7 pin connection, was missing the 30 amp fuse in slot 21.

you shouldn't be engaging the brake controller manually without a trailer hooked up that can use it. it's probably jumping across a connection somewhere & grounding out (hopefully).

BEDROCK

Thanks a bunch!!!
After further messing around. I realize the noise is the same noise that occurs every time I put the key 1/2 " or more into the ignition and sometimes when I step on the brake when the truck's NOT running. My question now is: what's that noise and why should the brake controller have anything to do with it. There should be no wire on the truck side of the connection going to the brakes, as the controller is inertia activated only. I guess I'm having a hard time understanding why there's power running to places all over the truck, making all kinds of beeps and buzzes, when the ignition isn't even on. And the controller manual said to move the manual lever w.o. trailer connected to test it.

kmac1036

ah, ok I had missed that in the book (pulled up the PDF). you got a lot nicer brake than I did I put the Pro Series POD in mine last week. which took the same harness as yours (cequent automotive makes pretty much all the brake controllers except for hayes. they all take the same oem adapter harness).

if it's not super loud I wouldn't worry about it, or your hearing is super sensitive to these types of noises, more so than mine. sounds like it's either the stop switch on the pedal or one of the relays. there's over a dozen relays & fuzes for the towing alone on the truck. that 7 pin connector does quite a bit: all the trailer lights (signal & marker), 12v power to charge batteries, and the electric brakes.