My 98 5.2L ram has a very weird problem with the vents...it's not the wild vent problem that everyone has...mine is this:

My ac blows extremely strong out the driver's side vent. The middle two vents hard have air blowing out of them..the vents on the passenger side are alittle more air flow than the middle but nothing compared to the drivers side vent! It is totally crazy...can anyone tell me what is going on..????

 

Probable clog inside the dash vent piping system. Try removing the vents and looking for a visible obstruction. If none can be found, try carefully snaking a cost hanger , or magic fingers tool down the center two vents and see if you come across anything.

The last thought would be that the actual tubing feeding the vents has cracked and is venting out the air for the center vents. You can feel around under the dash and feel for cold air where it shouldn't be.

A magic fingers tool is also called a cat's paw tool or claw grabber tool. Not sure of the correct name, but growing up we called them magic fingers.