No trailer brakes

[rburckhart]

When we got to our destination I wanted to move my slider hitch back to the maneuver position, so I set the lever, got in the truck, squeezed the dash lever, went to pull forward, and the trailer moved with the truck - twice! Checked my 7 pin connector on the truck (2015 F-250 SD 6.7) for voltage; got voltage to all pins except brake pin - got about 7-8 volts using the brake controller lever, but nothing when the brake pedal was pushed. Checked under hood 30 amp fuse and inside cab 5 amp fuse, both were good. Twice I got a temporary reading with pedal pushed, but jiggling the wires I couldn't make it come and go. Also had the DW pull the emergency cable, (truck running and plugged in) and felt nothing at the drums. Any ideas? Am I right in thinking with truck running and cable connected, I should be able to feel something with my hands on the drums as DW applies the brakes? Thanks!

[travelin texans]

I'm no expert, the newer trucks with built in brake controller the brakes are proportional, the more you press the pedal the more voltage goes to RV brakes. Hopefully ohers will chime in that know much more than me on how it all works.

[JRTJH]

The Ford OEM brake controller also uses the vehicle accelerometers to help mediate voltage to the brakes. If you're measuring the voltage with the vehicle in P and the tires "not turning" you won't "fool the computer" into believing that you're vehicle needs to provide power to the brakes to stop what is already stopped....

In short, you can't/won't measure a voltage output to the brake pin on the 7 way plug.

If you're trying to test the truck, you'll need more equipment than is normally in the home garage. If you're trying to test the trailer brakes, just pull the pin on the emergency break-away device. That will apply "full voltage" to the trailer brakes.

This article may help explain it a little better: https://www.tomorrowstechnician.com/the-trouble-with-troubleshooting-integrated-trailer-brake-controllers/

[rburckhart]

While I had the truck running and the trailer plugged in, I had DW pull the emergency cable and still felt nothing with my hands on the drums. We we arrived here, I wanted to slide my hitch back to allow me more room; I moved the hitch lever then got in the truck, applied the brake lever on the dash (which I've done numerous times in the past) and when I pulled the truck fwd, the trailer came with it (tried it twice)!

[bobbecky]

I would think that pulling the break-away switch would throw full 12 volts to the brakes, regardless of whether the truck was connected or not. I would be checking the wiring to the brakes on the trailer if the brakes don’t activate with the break-away switch.

[JRTJH]

^^^ What he said... While you may have an issue with the truck/IBC/7pin plug, you have a bigger problem with the trailer brakes/wiring if pulling the break-away switch plunger doesn't "lock up the brakes" (or at least, apply SIGNIFICANT braking effort)... Your "biggest problem" is in the trailer

[tech740]

Do you have a true battery disconnect that was in the off position? That would isolate power for the disconnect.

[rburckhart]

BREAKING NEWS! I actually think I might have solved my problem when I sanded the contacts on the plug and receptacle. Today I skinned a small spot of insulation off all of the feed lines at the brakes and checked for voltage, and was pleased to find it at all four brakes. Next, jacked up each wheel in turn, spun it, had the wife use the squeeze lever, release it and apply pedal as I spun them, and they all worked! Answered prayers! Thanks for your good comments!

[ChuckS]

Thanks for posting update and what you found. It may provide help down the road to another ... did you also verify the RV brakes all lock up when emergency brake cable pin is pulled? You should have had emergency brakes regardless of what the TV connection was doing