20
21
System Switch Continuity Check
Remove and label all wires from the system switch. Using an ohmmeter checks for continuity can be made. Continuity
reading should be as shown in the table below. Should the switch fail any part of this check it should be replaced.
Thermostat Continuity Check
Remove and label all wires from the thermostat. To check out the thermostat on cooling the thermostat bulb must be
above 60 degrees. Using an ohmmeter checks for continuity can be made. Continuity reading should be as shown in
the table below. Should the thermostat fail any part of this check it should be replaced.
(Some thermostats may have the terminals identified by the letters C, H and L)
Cooling
Only
Models
Cooling /
Heating
Models
CONTACTS MADE
OFF
NONE
L1 TO 2, 5 TO 3, 4 TO 6
L TO 9, COM TO L2
L1 TO2, 5 TO 3, 4 TO 6
H TO 9, COM TO L2
8 TO H, COM TO L2
L1 TO 8
L1 TO 2, 5 TO 1, 7 TO 6
H TO 9, COM TO L2
L1 TO 2, 5 TO 1, 7 TO 6
L TO 9 COM TO L2
LOW COOL
HIGH COOL
FAN ONLY
HIGH HEAT
LOW HEAT
CONTACTS MADE
OFF
NONE
L1 TO 2,3 TO COMP.
4 TO H, COM TO L2
1 TO H COM TO L2
L1 TO 2, 3 TO COMP.
L TO 4, COM TO L2
LOW COOL
HIGH COOL
FAN ONLY
ROTATE SHAFT
(VIEWED FROM THE FRONT)
CLOCKWISE TO STOP
COUNTER CLOCKWISE
TO STOP
READ CONTINUITY BETWEEN
2(C) & 3(L)
2(C) & 1(H)
Thermostat
Rear View
3
2
1
L
C
H
