Evaporator Core

Leaks in the evaporator core are the most difficult to find. Use the following procedure in order to test the core:
1. Turn on the blower fan to HI for 15 seconds or longer.
2. Turn off the blower fan.
3. Wait 10 minutes.
4. Remove the blower motor resistor.
5. Insert the leak detector probe as close to the evaporator as possible.
If the detector emits a solid alarm, a leak has been found.
6. Use a flashlight in order to visually inspect the core face for evidence of refrigerant oil.