Leak Test - Evaporator Core

One of the most difficult leaks to find is in the evaporator core. To leak test the core:

1. Turn the blower fan on HI for 15 or more seconds then shut it OFF.
2. Wait 10 minutes.
3. Remove the blower control module.
4. Insert the leak detector probe into the opening trying to get as close to the evaporator as possible. If the detector goes to a solid alarm, a leak has been found.
5. If possible, with a flashlight visually inspect the heater/ evaporator case and drain hole for evidence of refrigerant oil.