3-20 Ambient Resistance
Temp. (˚F) Value
60 75.24 kΩ (±11 kΩ)
68 62.57 kΩ (±8 kΩ)
70 59.79 kΩ (±8 kΩ)
80 45.80 kΩ (±7 kΩ)
90 36.94 kΩ (±6 kΩ)
TEST PROCEDURE RESULTCOMPONENT
N.O. and C Terminals
Set the ohmmeter to the
R x 1
scale, and measure the resistance
between the normally-open (N.O.)
and the common (C) terminals of
the switch.
Switches (with wire leads re-
moved). All of the switches are
measured in the same manner.
Temperature Probe
a) Fan Motor - Normal = 130
to 155 ohms.
Set the ohmmeter to the
R x 1
scale, and measure across the
terminals.
a) Normal - The meter indi-
cates infinity.
b)Abnormal - The meter
indicates zero ohms (a
short).
N.C. and C Terminals
Set the ohmmeter to the
R x 1
scale, and measure the resistance
between the normally-closed
(N.C.) and the common (C) termi-
nals of the switch. b) Abnormal - The meter
indicates infinity.
a) Normal - The meter indi-
cates continuity, or zero
ohms.
Fan Motor (with leads discon-
nected).
Blower Motor (with leads dis-
connected)
Set the ohmmeter to the
R x 1
scale, and measure the:
a) High speed windings (blue
and black wires).
b) Low speed windings (blue
and white wires).
a) Normal - High speed: 25
to 45 ohms.
b) Normal - Low speed: 45
to 65 ohms.
C.
N.C. CONTACTS
N.O. CONTACTS
Set the ohmmeter to the
R x 1
scale, and measure the resistance
between the motor terminals.
Stirrer & Turntable Motors (with
leads disconnected)
a) Normal - 1 to 4 ohms.
b)Abnormal - Infinite or
zero ohms.
Set the ohmmeter to the
R x 10 k
scale, and measure the tempera-
ture probe with the leads posi-
tioned at either terminal.