Troubleshooting Guide

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to verify the performance of the refrigeration system before leaving. If it still
does not start, continue to the next step (d.).
• If none were disconnected, continue to the next step (d.).
d. Turn the ON/OFF toggle switch back ON. With the side panel still off, stay clear of
the fan motor and repeat steps 2 and 3 above.
e. If the COMP LED is on but the compressor is not, remove the locking tab
connectors from the compressor BRN and ORG terminals and measure the voltage
at the pins on the Internal Control board:
• If the voltage is 120VAC (nominal) then the problem lies with the run capacitor,
the connections at the compressor or the current limiting switch under the
compressor cap. Turn the ON/OFF toggle switch OFF and unplug the unit.
o Disconnect the wires connected to the run capacitor and the orange wire
connected to the Internal Control board. Measure the capacitance of the
run capacitor – it should be 45 microfarads ± 5% for the 70/95pt or 50
microfarads ± 5% for the 130pt. If not, replace the capacitor (5458 70/95pt
or 5594 130pt).
o Measure the resistance across the compressor harness wires. Actual
measurements may be a little different, but should be approximately:
Orange – Red: 1.1Ω, Orange – Brown: 1.9Ω, Red – Brown: 2.7Ω. If the
Orange-Red and Orange-Brown measurements are open (infinite) but the
Red-Brown measurement is normal, then the compressor overload switch
(5547 70pt / 5548 95pt / 5574 130pt) under the compressor cap needs to be
replaced. If just one is open, then it is likely a connection at the compressor
has come loose – remove the compressor cap and check the terminal
connections.
• If the voltage is 0 VAC, replace the Internal Control board (5444).
5. If the compressor does start, there are four reasons why an E4 diagnostic code would
appear: the system has lost refrigerant, sudden changes to the environment, turning on
too soon after having turned off or the Frost sensor and high temperature sensor are
reversed.