Norcold 442 Repair Manual page 19

B101
5. If preceding checks did not re-
veal the cause of malfunction,
then access to the control
panel is required as shown in
Figure 3.43. The first step in
gaining access is to remove
the two control knobs (A), then
remove the (6) Phillips head
screws (B) as shown. Once
control panel has been re-
moved, you need to remove
(2) Phillips head screws (C).
Then pull the control mounting
bracket forward. This allows
access to the controls.
6. Step 6, 7 & 8 apply to 3-Way
units only. If you are checking
a 2-Way skip to Step 9. Set AC-
ELEC STDBY-DC switch to
ELEC STDBY (not DC). With a
Volt-Ohm meter, check for 12
Volts DC between Point 1 and
ground shown in Figure 3.44.
Then check Point 2. One test
point should read 12 Volts
and the other should read 0
Volts (the point which reads
12 Volts is the switch input
terminal). This confirms volt-
age to the switch. If neither
test point reads 12 Volts,
check for bad connections.
7. Set AC-ELEC STDBY-DC
switch to DC; Mode Selector
to ELEC; Thermostat
COLDEST.
8. Check for 12 Volts at Point 1
and ground and Point 2 and
ground at switch as shown in
Figure 3.45. Normal readings
should show 12 Volts on both
terminals. If 0 Volts are read,
check wiring connections.
9. With AC-ELEC STDBY-DC
switch to DC; Mode Selector to
ELEC; Thermostat to COLD-
EST, check for 12 Volts at each
terminal of the combination
control and ground as illus-
trated in Figures 3.46 and 3.47.
Normal readings should show
12 Volts on both terminals.
10. If there is 0 Volts on both ter-
minals, check wiring connec-
tions. If there is 12 Volts on
only one terminal, replace the
Combination Control. If unit is
Chassis
Ground
Figure 3.44 12 Volt Check at Switch Inlet
Chassis
Ground
Figure 3.45 12 Volt Check at Switch's Center Contacts
to
Figure 3.46 12 Volt Check at Combination Control
Figure 3.47 12 Volt Check at Combination Control Switch
3-19
Chassis
Ground
Chassis
Ground
Rear View of AC-
ELEC STDBY-DC Switch
Rear View of AC-
ELEC STDBY-DC Switch