Air conditioner air vents not working - front of trailer

Speaking of aluminum tape....do you guys think this could be the problem? Lol

Wicked advice Bob. I'll have a look. Except I always
use aluminum tape. :).

Maybe they forgot to install the duct. Stranger things have happened. Pop one of the circular vent off and make sure there is duct. Then drop the lower cover and make sure it is properly taped. The front registers are fed off one side of the AC, the rear from the other side. One side should mirror the other. If not, break out the duct tape. This would also be a great time to tape up the ducts around the ceiling registers where they cut big circular holes for the registers. There should be no leaks into the roof area.

It's totally possible they forgot to hook them up....not sure though if there were any suggestions or something I am missing. No combination of open or closed vents make the front vents work...

It's possible the ducting is not connected. Are you able to close the working vents and see if the front vents start to work?