5. What are the ambient conditions during complaint?
6) What is the charge and air flow condition?
If compressor, fan or line noise is suspect conduct the following procedures if applicable:
Isolate the compressor and fan from each other and run with only one on at time.
If line noise, does applying pressure in any particular location around suspected noise change the tone?
If noise is suspected in the fan motor, blade or grille observe the following if applicable
If noise is a grille, panel or louver observe the following as applicable: