Service Manual

34
3-minute Comp delay timer terminates: Have Comp and ConFM energized after DH
is de-energized for 3 minutes? If not, check for 115VAC between CM C1 and CM N5.
If 115VAC is not present, replace CM. If 115VAC is present between CM C1 and CM
N5, check for 115VAC on CR coil (terminals 5 and 6). If 115VAC is not present between
CR5 and CR 6, check continuity of HPS. If open, allow time for HPS to reset. If HPS
does not reset, replace HPS and diagnose reason for HPS activation. See "IV.A.2.7)c)
HPS Activation." If 115VAC is present between CR 5 and CR 6, and Comp and ConFM
are not energized, check for 115VAC between CR terminal 4 and neutral (W wire) and
CR terminal1 and neutral (W wire). If 115VAC is present between CR terminal 4 and
neutral (W wire) and not CR terminal 1 and neutral (W wire), replace CR. If CR is good
and Comp or ConFM are not energized, check for 115VAC at Comp terminals, Comp
protector (internal on 1-section, external on 2-section), start components, and Comp
and ConFM motor winding continuity.
8-minute EvapFM delay timer terminates (3-minutes on manually initiated defrost):
Have EvapFM energized 5 minutes after Comp and ConFM energized? If not, conrm
that the door(s) are closed and DS contacts are closed. Check EvapFM blades for
binding. Next, checkfor 115VAC at DSR terminals 7 and 8. If 115VAC is not present,
check DS continuity. If 115VAC is present, check DSR coil continuity and contact
continuity between terminals 6 and 4. If coil or contacts are open, replace DSR.
Next, check for 115VAC between CM F6 and CM N5. If 115VAC is not present, check
between CM L3 and CM N5. If 115VAC is present between CM L3 and CM N5 and not
between CM F6 and CM N5, replace CM. If 115VAC is present between CM F6 and CM
N5, check EvapFM continuity.
13-minute temperature display delay timer terminates: Conrm cabinet temperature
appears on DM 5 minutes after EvapFM energizes.
If components fail to start after delay timer terminates, replace CM.
10) MH and PH Diagnosis: Check that MH and PH energize. Check for 115VAC at MH
and PH. If 115VAC is not present, check power supply and continuity of power switch.
If 115VAC is present, check amp draw of MH or PH. If an amp reading is not present,
check the continuity of MH or PH.
Legend: CM–control module; Comp–compressor; ConFM–condenser fan motor;
CR–compressor relay; CTh–cabinet thermistor; DH–defrost heater;
DM–display module; DSR–door switch relay; DTh–defrost thermistor;
EvapFM–evaporator fan motors; HPS–high-pressure switch; MH–mullion heater;
PH–perimeter heater; TXV–thermostatic expansion valve