you have a vacuum line disconnected under the hood. The connections is on the drivers side of the motor right below the fuel injector rail.
Your air mix door is stuck, follow the cable from the temp control to the heater/ac unit and see if the flapper is moving, if not the door itself may be stuck or broken and you'll need to get in there and replace it.
If it's stuck in defrost your battery died and messed up the computer. Disconnect battery for 5 or more min. My 96 cooled and heated ok but was stuck in defrost
Check for a vacuum leak either under the hood or under the dashCheck the vacuum actuators under the dashCheck the selector control Defrost is the default for this system
Yes, pull the A/C fuse or disconnect the compressor.
Sounds like a stuck blend door.
The AC on a 1998 Dodge Ram 1998 will only be blowing out the defrost vent if the air handler is not set properly. This can result from a piece of debris getting stuck or a faulty flap.
does fan door motorized or on a vaccuum line when you switch from AC to defrost?
Yes, it will run when in defrost or mix.
the ac drain is stopped up locate under hood on passenger side on fire wall
Check for a vacuum leak either under hood or under dash Check the operation of the vacuum actuators under dash Check the operation of the selector switch Defrost is the default settting for this system
Yes, the ac will run in the defrost position to dry the windshield.
If it's stuck in defrost your battery died and messed up the computer. Disconnect battery for 5 or more min. It worked on my 96