TECH SHEET - DO NOT DISCARD
PAGE 7
FOR SERVICE TECHNICIAN’S USE ONLY
PART NO. W10054150
TEST #3
Drive Motor Circuit
This test will check the wiring to the motor
and the motor itself. The following items are
part of this motor system:
–
Harness/
connection
–
Thermal fuse
–
Belt/belt switch
–
Drive motor
–
Centrifugal switch
–
Door switch
–
Machine control
electronics. See ESD
information, page 1.
1.
Unplug dryer or disconnect power.
2.
Access the machine control electronics
and measure the resistance across P8-4
and P9-1. See Accessing & Removing the
Electronic Assemblies, page 11.
➔
If resistance across P8-4 and P9-1 is in
the range of 1 to 6 ohms, replace the
machine control electronics.
➔
Otherwise, go to step 3.
3.
Check the wiring and components in the
path between these measurement points
by referring to the appropriate wiring
diagram and strip circuit, pages 4 and 5.
4.
Check the thermal fuse. See TEST #4b,
page 9.
5.
Check the belt switch and drive motor.
Access the belt switch and drive motor by
removing the front panel/drum assembly.
See Removing the Front Panel/Drum
Assembly, page 11. Slowly remove the
drum belt from the spring-loaded belt
switch tension pulley, gently letting the
pulley down. See figure 5.
6.
Remove the white connector from the
drive motor switch. See figure 6.
7.
Using figure 7, check for the resistance
values of the motor’s Main and Start
winding coils as shown in the following
table.
NOTE:
Main and Start winding coils must
be checked at the motor.
WINDING RESISTANCE
Ω
CONTACT POINTS OF
MEASUREMENT
MAIN
1.4–2.6
Blue wire in back at
pin 4 and bare copper
wire on pin 5 of black
drive motor switch
START
1.4–2.8
Blue wire in back at
pin 4 and bare copper
wire on pin 3 of black
drive motor switch
➔
If the resistance at the motor is correct,
there is an open circuit between the
motor and machine control
electronics. Check for failed belt
switch.
➔
If the Start winding resistance is much
greater than 4 ohms, replace the motor.
8.
Check the belt switch by measuring
resistance between the two blue wires as
shown in figure 8, while pushing up the
belt switch tension pulley.
➔
If the resistance reading goes from
infinity to a few ohms as pulley arm
closes the switch, belt switch is OK.
If not, replace the belt switch.
➔
If belt switch is OK and there is still an
open circuit, check and repair the
wiring harness.
9.
Door switch problems can be uncovered
in the Door Switch Diagnostic Test, page 1;
however, if this was not done, the
following can be done without applying
power to the dryer. Connect an ohmmeter
across P8-3 (neutral, white wire) and P8-4
(door, tan wire).
➔
With the door properly closed, the
ohmmeter should indicate a closed
circuit (0–2 ohms).
➔
If not, replace the door switch
assembly. See figure 11, page 10; and
Removing the Front Panel/Drum
Assembly, page 11.
Belt Switch
Tension Pulley
Belt Switch
Drum Belt
Figure 5.
Slowly remove drum belt.
Main Winding:
Blue Wire in Back and Bare
Copper Wire (5 Position)
Start Winding:
Blue Wire in Back and Bare
Copper Wire (3 Position)
Figure 7.
Main and start winding
measure points.
Belt Switch
Tension Pulley
Blue Wires
(Back and 4 Position)
Figure 8.
Checking the belt switch.
Drive Motor
Switch
White
Connector
Figure 6.
Remove white connector.
