Jeep AC blows cold air at defrost and feet but not through vents

It's the vent actuator, it moves the baffle that changes the direction of the air flow.
Here is a video of a broken vacuum hose that creates the same problem.

It could also be a failed actuator.

When the fan motor is loud it means its out of balance. Kind of like a dishwasher.

Could a business card or two have slipped through the defrost vents ? or maybe leaves have accumulated in the fans squirrel cage.

A heater motor isn't hard to remove. Usually above your feet on the passenger side held in with 3 or 4 screws and one heavy wire.

Well this is different since most questions now are about no heat.
If one ac line is cold and the other is warm, I would suspect a blend door under the dash is not working. The blend doors direct air thru the heater core and the vents.

make him do it again... ?

Its your climate control unit

the mode door motor is bad

Check for vac leaks. Any small leak can cause erratic vent door operation.

Check under your hood for a loose or leaking vac line , The A/C system on your jeep uses manifold vac to move the air mix doors and with no vac the air mix door will move into the defrost position. Find your vac leak and that will fix your problem.

Maybe your dashboard vents are clogged, obstructed or stuck in close position somehow.

If not, check the air hoses that carry the cooled air to the main vents are not clogged, bent, ripped or simply detached.
If its practical for you, check if they are correctly placed, clean and general conditions are ok if you can.

If above are not the issue, go to check outlets of the A/C unit, its filters for the possible reason.

vacume hose off or cracked it wont change to floor heat ooorrr field mice have made them selves a home in your heater box