Evaporator Core

Finding leaks in the evaporator core is very difficult. In order to leak test the core, complete the following steps:
1. Turn the blower fan to the HI position for 15 seconds or longer.
Then, turn the blower fan to the OFF position.
2. Wait 10 minutes.
3. Remove the blower motor resistor.
4. Insert the probe of the leak detector as close to the evaporator as possible.
A solid alarm indicates the discovery of a leak.
5. If possible, visually inspect the core face for evidence of refrigerant oil. Use a flashlight.