2011 dodge journey sxt I only get cold air on the drivers side when AC is on.

Hello, When you select a temperature for the air coming from the vents, you are actually telling the blend door actuator to move a blend door inside the A/C housing/duct. These blend doors allow for the hot air from the heater core and the cool air from the A/C evaporator coil to mix at the rate determined by the position of the door. So if it turns one way, it lets in more hot than cold air, and the other way will do the opposite. This is how you can have a broad range of air temperature from your vents. When only one temperature of air is coming from the vents, you can fairly well guess that the blend door actuator is no longer moving the blend door. Especially with Dodge/Chrysler/Jeep. Check your fuses, if you find none blown, seek diagnostics to determine if the blend door is broken, the blend door actuator is no longer actuating, or the control unit is not telling it to actuate.