1. Low-side pressure reads lower than normal.
2. High-side pressure reads lower than normal.
3. Low amperage reading. Read the amperage the compressor draws. Do it by placing the ammeter around the wire to the compressor run or common terminal.
(See fig. 124) The nameplate on the unit will indicate the correct amperage the unit should draw while running, shown as FLA, as opposed to the amperage it draws at the instant of starting, shown as LRA on the nameplate (or in the reference book mentioned on page 105).
4. Little or no frost on the evaporator coil.
5. Unit runs continuously (nonstop).
6. Unit starts immediately after it is turned off. (Instead of the usual two- to-three-minute delay for the head and back pressures to equalize through the capillary tube during the off cycle.)
7. In cycle-defrost units, the temperature in the ice compartment drops below normal while the temperature in the fresh-food compartment rises above normal because an insufficient amount of vaporizing refrigerant circulating through the evaporator becomes superheated by the time it reaches the last passes of the coil in the fresh-food compartment.
Since the thermostat sensing bulb is attached to the lower part of the coil in the fresh-food compartment, it never allows the thermostat contacts to open. This causes the unit to run continuously and the temperature in the freezer compartment to drop below normal.
