Troubleshooting - Procedure E - Norcold DC0040 Service Manual

Troubleshooting – Procedure E
Thermistor Operation Verification
To measure the resistance of the
evaporator thermistor, turn the
refrigerator to the OFF position.
Disconnect the three-pole connector
(Figure 7), and measure resistance
across the two pins. (Figure 8)
Check the evaporator thermistor by
measuring the temperature and
resistance of the thermistor. Refer to
Thermistor Temperature
( °F )
10
20
30
40
50
60
70
80
90
Figure 7 – Evaporator Thermistor
Connection (inside power supply)
Evaporator Thermistor Resistance
( °C )
0 -18
-12
-7
-1
4
10
16
21
27
32
Table 1 for a listing of acceptable
resistance ranges.
In general:
W
1.6K – 29K
¥W
= defective thermistor. An open
thermistor will stop normal compressor
operation. Replace the defective
thermistor.
Resistance Allowable
Resistance Range
W
9.7 K 8.7 - 10.7 K
W
7.8 K 7.0 – 8.6 K
W
6.4 K 5.7 – 7.0 K
W
5.3 K 4.8 – 5.7 K
W
4.5 K 4.0 – 4.9 K
W
3.6 K 3.2 – 4.0 K
W
2.8 K 2.5 – 3.1 K
W
2.1 K 1.9 – 2.3 K
W
1.9 K 1.7 – 2.0 K
W
1.8 K 1.6 – 1.9 K
Figure 8 – Measure Resistance
Across Pins
= good thermistor.
W
W
W
W
W
W
W
W
W
W
(Table 1)
7