If you didn't order the trailer camera option and now you want a camera on your trailer and have it displayed on the factory screen..
Here's what I did.

It can be on full time while driving. All Sync3 features still work but you have to switch back and forth between the Sync screen video and the camera video, if you want to see the regular Sync screen.
The video interface basically hijacks the Sync screen.
This interface needs a slight mod to have the trailer camera work when the truck is put into reverse, or else the truck reverse cameras take over the screen and the trailer cam disappears.
It has 2 video inputs, one reverse camera input (that works when truck is in reverse), a RGB HD input (I haven't figured that out yet, but I don't care)
And it can be integrated with some kind of navigation thing that I don't care about.
You could use one of the vid ins for a front cam...I read a lot of guys are searching for a way to have a front cam.

As for the trailer camera itself, you just need to figure out how to get the signal from your camera to the composite vid input of the interface.
My trailer camera is wired up to the front of my trailer then I go wireless to a receiver I mounted in the dash.
The interface is small and mounts (lays) perfectly ontop of the cd module and under the screen
The interface cost me about the same as if I had ordered the trailer cam option.

Video interface for Ford SYNC 3

 

My 5th wheel has a wireless camera, so bridging to wired to this system may be a solution for us long body (45ft) RVs.

Where does this interface plug into our sync system?

 

A main harness plugs into the back of the cd. Then the cd harness back into the main harness. That's were it gets the power, ground, reverse signal, and some can buss info.
Then one of the connectors in the back of the screen plugs into the interface and then from the interface back to the screen.
It's all simple plug and play.

You just need to figure out how to go from your wireless to a composite rca input

 

I thought some where while browsing on this topic I saw a wireless receiver that will plug into those plugs. That way you can use your wireless cam into a wired unit. Have to Google that one

 

Do you have any pics of the install? Is there a separate button you push to cycle between Sync and any of the other inputs? I'm looking to add a trailer camera and a front camera, this looks like it might fit the bill.

 

I don't think I want to give up my Sync that much. I'm thinking of going with a totally independent system, and I'll attach the monitor to the rear view mirror when I'm towing.

 

With the device he's using you don't give up your Sync at all. You hit a button to switch the video output on the screen to one of your auxiliary cameras. Then when you're done you hit the button again and you're back at your Sync screen like normal.

 

What I meant was that I think I'd rather glance up at a monitor on my mirror, then back to my Sync screen for nav, music, or whatever, without pressing a button. I'm still in the planning stage, though. I'll probably change plans a few times before I pull the trigger.

 

Yes this^^^
Except push the button 3 times to get back.
That cycles through all the video inputs.
It would be easy to hook another cam up to it.

Also I have it hooked to an upfitter switch so I can go instantly to the trailer back up cam when I'm in reverse (if I don't already have the interface screen displayed)

Sorry no pictures of install. It fits nicely on top of the DVD player behind the bezel.

Then there is a little black button to to stick on in an easily reached area. I put it beside the little grills for the auto temp sensor

 

Sweet, I think I'm going this route with a front camera and a trailer camera. Seems the easiest to integrate with everything I want.

 

This is the wireless unit I used.
It breaks up sometimes, not enough for me to fix it. Probably wouldn't if I mounted the receiver behind the rear seat instead of behind the Sync screen.