I have a 2011 F-150 EB, it has the backup camera & alarm. I seem to remember when I first got the truck, that the alarm would not sound when a trailer (with working light system) was connected (factory tow/light package). I connected a trailer that had questionable lights & it blew a few fuses, I got that fixed & the trailer light output works again, but the backup alarm alerts now, even when a working trailer/light system is attached. I took it back to the dealership, but they tell me this is how it is supposed to work: alarm sounds in reverse anytime a trailer is connected, regardless of the working lights or not.

With as smart as the computer system is, it would be a simple thing to detect the trailer circuit & turn off the alarm, so I disagree with the dealer - anyone have experience or knowledge on this?? I can't stand the alarm sounding when I am focused on backing a trailer...

 

On my 2010, the backup alarm does disable when a trailer is plugged into the 7 pin. Worst case you can hit the reset button and turn off the back up sensors when hooking to a trailer, then turn it back on later.

 

Doesn't sound when connected to my trailer in reverse.

Find another dealer?

Maybe first check another trailer to be sure it isn't something still funny with yours?

 

If you have a fuse blown, the truck won't know the trailer is connected and so still set the alarm off.

 

I bet there is one more blown fuse.

 

My backup sensor goes off even if my trailer is plugged in. I plug it into the 4pin though.

 

Thanks for the feedback - my primary question was RE whether the alarm goes off when the 7 pin connector is used, thanks. I have convinced the dealer that it is supposed to turn off, they have asked me to bring them my trailer if needed...

On another note: where in the world is this "alarm reset button" or whatever it is called?? I have never seen such...

 

mine doesn't sound with my car hauler... it did when I had bad wiring to the brakes on the trailer....
so to me it may look for the trailer brake feed- low voltage signal??..

 

See attached extract from the owners manual. Not alarm reset, but just reset buttom, has several uses.

 

The trailer has to have properly functioning electric brakes for the truck to recognize it. Plugging into the 7-way, in and of itself, does not make the truck see the trailer. There has to be proper impedance in the brake circuit.