Ran and tested system upon arrival. Suction and liquid line pressures were good, superheat and subcooling was good. By then there was almost no temperature split. Inspected ductwork in attic, all appeared to be fine. Checked static pressures of system, total static pressure of .5-.6. Called Rob for assistance with the problem. He directed me to take amp draws on the electric heat strips to ensure that they are not engaging. Attempted to duplicate what the customer was complaining about and what I had seen. Unable to do so. Disconnected low voltage wiring to electric heat strips to ensure they were not the problem. While checking for amp draws in the electric heat strips the outdoor unit shut off and turned back on a couple of times. No fuse were blown during this process. Line voltage to the unit was fine, but it was dropping low voltage to outdoor unit. Buttoned up system and ensured it was running before I left. Need to come back with more experienced technician to assist in proper d