Upfitter antenna?

[Bluebeard]

I recently bought a used F350 flatbed and we have a Grandby coming from FWC in April. Preparing the truck I found three coaxial cables under the rear bench that go to a small, rectangular box on the cab roof that I’m guessing is an antenna. The cables are labeled WLan, Iridium, and GPS. I happen to have a Garmin GPS, and an In Reach that uses the Iridium network, but I don’t know if having the hardwired antenna is of any benefit, or how I’d put it to use. Any tech gurus care to help me sort this out? Thanks in advance

 

[Fishyhead]

I use external antennas with my portable Garmin chart plotters and they seem to pick up more gps satellites quicker than with the internal antenna. In practice, it made no difference since the GPSs were always on the dash with an unobstructed view out the windshield.

I now use a newer on-road garmin to get to the trail then switch to a handheld chart plotter that I also use on the motorcycle.

PS: having an external antenna meant connecting and disconnecting one more wire from the device when I parked in the city overnight. It's PITA on some mounts and mounting locations.

 

[Bluebeard]

Than you for the insights

 

[rando]

I am going to guess that antenna was installed by the prior owner and not Ford.

In general there is no need for an external antenna for either an inReach or GPS if they are mounted on the dash. Most of the inReach and handheld GPS devices don't even have the provision for a an external antenna. Also, will the antenna itself be covered by the cab over on the camper?