Diagnosing Ice Thickness Control Circuitry; Ice Probe Light On; Ice Probe Light Off - Manitowoc S300 Technician's Handbook

Diagnosing Ice Thickness Control Circuitry

PROBLEM: ICE MACHINE DOES NOT CYCLE INTO
HARVEST WHEN WATER CONTACTS THE ICE
THICKNESS CONTROL PROBE
Step 1 Bypass the freeze time lock-in feature by
moving the ICE/OFF/CLEAN switch to OFF and back
to ICE.
Step 2 Wait until water starts to flow over the
evaporator (freeze cycle).
Step 3 Disconnect the ice thickness control from the
control board, then connect a jumper wire from the
control board to any cabinet ground and monitor the
ice probe light.

Ice Probe Light On

• The ice probe light comes on, and 10 seconds
later, the ice machine cycles from Freeze to
Harvest.
• The ice thickness probe is causing the
malfunction.
• The ice probe light comes on, but the ice machine
stays in the Freeze sequence.
The control board is causing the malfunction.

Ice Probe Light Off

• The ice probe light does not come on.
The control board is causing the malfunction.
If you suspect a defective probe check for continuity
from the ice thickness probe to the connector.
• With continuity DO NOT change the probe.
• Without continuity, the probe is defective.
148 Part Number 80-1479-3 7/10