Check Rpm of engine shaft

Check Rpm of compressor shaft

Start and stop the evaporator blower

Start and stop the compressor electro magnetically

LPC, HPC and Blower-switch

Thermostat, Electromagnetic clutch, on-off control

Thermostat, Thermostatic expansion valve, Blower-switch

Thermostat, Low-pressure control and high pressure control

Drain pan is leak proof

Leakage of evaporator coil

Poor insulation at the bottom of drain pan

Worn out shock absorbers on the bus wheels

Chokes the orifice of TEV

Blocks the orifice of AEV

Closes the orifice of TEEV

Closes the orifice of capillary

Moisture in the system

Fully evacuated system

Excess of lubricant in receiver

Non condensables in the system