2004 ram only blows air out vents and not defrost. blows out vent even if changed to defrost but change somtimes

A vent flap actuator probably needs to be replaced. It's what moves your vent flaps from heat to A/C or to plain "vent air" when you change settings.

The discussion in the link includes vent flap actuators. Unfortunately, they also include the infamous no low speed fan problem too.

Cannot get any air from dash vents while defrost and floor vents work fine...

Your particular actuator will be a different one than they found.
They're all a absolute pain to get at because they can be well buried in the dash. I would start looking under the dash on the passenger side, that's where most of the air control is. Cannot get any air from dash vents while defrost and floor vents work fine...

mode motor is bad

usually a faulty blend door under the dash

Common question on this site. On late model cars, the vents are controlled by blend door motors. Small electric motors open and close doors to direct air flow.
Chances are you have a blend door that is stuck or a failed motor.
The default position is the defrost to make sure the windshield is always clear.
Someone will need to look behind the dash to see if all of the doors will move on demand.

There is a blend door acuator which moves when u change your settings. Its a electric motor. Down under dash, Will need a mech and a heating and cooling diagram to find where the motor is,

Sounds like the "Blend Doors" are not completely closed (or opened). The Blend Doors open and close to direct the air from the blower motor to the vent selection you have made on the control panel (defrost on windshield, floor, front, etc) You may need to try various selections to see if the blend doors actually open or close. If no changes, it could be a blend door actuator failing.

May be I can help,you have a vent door actuator motor that has gone [email protected]

Is it a new vehicle? I had a new vehicle that had the same problem. Answer was that the holes weren't punched out of the vent.

Sounds like you have a supply vacuum problem. When you lose supply vacuum to the control head it defaults to defrost.

Try replacing the cabin air filter.