Service Manual
Table Of Contents
20
f) EvapFM Diagnosis: Conrm that EvapFM(s) energizes 30-sec. after startup.
If not, conrm DTh is above 32°F (0°C). If above 32°F (0°C), wait for evaporator to
cool down. Next, conrm doors are closed and DS engaged, check DS continuity.
IfDS is engaged and contacts are open, replace DS. If DS is engaged and contacts
are closed, check for 115VAC at CM 5 (F) dark blue (DBU) wire to neutral white (W)
wire. If 115VAC is not present, replace CM. If 115VAC is present, check EvapFM
blades for binding and EvapFM continuity.
g) HPS Activation: Conrm ConFM is energized and fan blade turns freely.
Conrmcondenser coil is not clogged or restricted. Conrm there are no restrictions
in the refrigeration circuit (TXV and drier). Let refrigeration circuit pressures equalize.
IfHPS does not reset and pressures are equalized, replace HPS. Ifpressures are not
equalized, reclaim refrigerant and diagnose refrigeration circuit restriction.
6) Cool Down Achieved–PH, MH, and DrH continue. CTh cools to 3°F (1.7°C) below
setpoint. Comp icon turns off and Comp and ConFM de-energize. EvapFM icon
stays on and EvapFM continues. 60-sec. later, EvapFM icon turns off and EvapFM
de-energizes.
a) Diagnosis: Conrm Comp icon turns off and Comp and ConFM de-energize. Ifnot,
and Comp and ConFM were energized longer than 2 min., check CTh status.
See"II.D. Thermistor Check." Replace as needed.
b) CM, Comp, ConFM, and EvapFM Diagnosis: IfCTh ohm reading is in proper range
and Comp continues, check for 115VAC at CM 1 (C) (V) to neutral (W). If115VAC
is present at CM 1 (C) (V), replace CM. 1-min. after Comp icon turns off, conrm
EvapFM icon turns off and EvapFM de-energizes. If not, check for 115VAC at
CM 5 (F) (DBU) to neutral (W). If 115VAC is present, replace CM.