Lot53yahoo.commy jeep x 2005 a/c blows out the defrost ,did work fine then just went bad . i cant find the actuator loc or is it a vac leak ??

There are usually 3 or 4 actuators. One is for center vents, one is for defrost, one is for heat and one is for outside air. You need to go online in your browser and put in '2005 Jeep Gran Cherokee A/C Actuators'. You will get a diagram that shows the location of each actuator I have listed. Usually there are 1 or 2 actuators you can get to and change without removing 1/2 of the dash. If you are lucky it will be located on the passenger side next to the center console going towards the firewall.

Adjust or replace boot door switch. Check for vacuum leak in dash control unit, or bad door actuator.

If the air does not blow out of the defrost vents, check the control and the vent door actuators for a vac leak.

Usually a sign of a vac leak between the engine and the control on the dash or the blend door.
The defrost position is the default when there is a problem with the system so that the windshield stays clear in wintertime.

Vac actuator at heater box is either bad or vac line came off or is cracked

I also say its a vacuum issue. Any vac leaks on the engine?

The Blower Motor Resistor is a common problem in your car but not for the problem you describe. When the Heat/AC won't blow on all speeds, the blower motor resistor is at fault. When air won't blow out of vents, bi-level, or floor the problem is the blend door actuator. This is vacuum driven and diverts the air to where you select. When air will only blow from one place (usually the defrost) then the blend door actuator is the problem. This can sometimes be corrected if there's a vacuum leak (usually under the hood in front of the passenger you'll find the vacuum line and can trace it backward to find a leak). If no leak can be found, the blend door actuator itself is defective and needs replacement.

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.

There is a flap that directs the air. the flap is controlled by a vacuum actuator. This is located inside the venting. The actuator is connected to little vacuum hoses that attach to the temperature control switch. Either the flap is stuck, or the actuator has gone bad.