1998 Plymouth Voyager filter

Inspect the evaporator and HVAC housing for leaves or other foreign material that may be blocking the air flow through the evaporator. If the build up is excessive, replacement of the evaporator may be required.
With the parking brake applied and the transmission in Park, start the engine and let idle. Put the temperature control to full hot, blower speed to HIGH, select the PANEL and RE-CIRCULATE modes. Open all windows about 13 mm (1/2 in.). Disable the A/C compressor clutch by disconnecting its wiring connector or the wiring connector to the A/C pressure switch.

NOTE: This procedure heats the evaporator and causes moisture to evaporate faster. The slightly open windows allow moisture to escape the vehicle without loosing much heat. Sometimes, you may see a "fog" clouding the windows. After this "fog" has disappeared continue to operate the heater for another 5 minutes. If the "fog" never appeared, operate the heater for a minimum of 30 minutes.

Turn the ignition switch to the OFF position

Gain access to the evaporator cavity to apply the evaporator cleaner