Trailer Brake Help

[Billrog]

Put a ground jumper wire from the truck frame to the trailer frame and try it. Booster cables would work.

 

[kevin37b]

Are the grounds the same on the Dodge and the Ford ? Has a wire got pinched ? Good to see you around .

 

[wcampbell47]

My flatbed is in the shop so I need to tow my GN with my old F350. All lights work but the trailer brakes will not activate either with the slider or pedal. GN connected to the flatbed truck and brakes work.

F350's Prodigy controller show no connection to the GN.
Brakes work fine when the F350 is connected to my other trailers.

Controller checks out fine, both for the slider and brake switch.
Using a 6-7 way adapter, but....
Voltage checks out fine at the 7 way trailer brake output terminal on the adapter when the brakes are applied.

Switched trailer brake and 12 volt constant connections on the trailer's plug to check brakes.
Plugging in with the 12 volt connection instantly activates the trailer brake magnets.
This would indicated that the trailer brake wire is working.
Switched the wires back to normal position and no brakes / controller shows not connected.

So...what am I missing?

I found two fuses blown on my '09 with similar issues.

If you need a manual for your truck try this:
Ford F-35 Owners Manuals - JustGiveMeTheDamnManual.com

 

[RDrancher]

After running new wires from the trailer plug to the trailer and bypassing the breakaway, the controller went from reading "no connection" to "short." Very confusing, but the frustrating ordeal has finally come to an end. While I was changing out the water pump yesterday, my FIL stuck his finger into the truck's plug socket and noticed that one of the posts moved a tad. Yep, the trailer brake post. While putting enough straight pressure on it, the post would actually slide back flush. I'm really glad that's over...it was making my head hurt.