Table of Contents
Advertisement
section 6
Diagnostic tests
TEST 5 - CHECk STEPPER MOTOR CONTROL
PROCEDURE:
1. Remove air cleaner cover to access stepper motor.
2. Physically grab the throttle and verify the stepper motor, linkage
and throttle do not bind in any way, if any binding is felt repair
or replace components as needed. Some resistance should be
felt as the stepper motor moves through it's travel.
3. Physically move the throttle to the closed position by pushing
the throttle down as looking from above.
a. Place the idle control switch to off.
b. Place the start switch to start and watch for
stepper motor movement it should move to the
wide open position during cranking. Once the
unit starts the stepper motor should move the
throttle to a position to maintain 60 Hertz.
STEPPER
MOTOR
LINKAGE
Figure 6-2. – Stepper Motor, Linkage and Throttle
Seen From Above
FULL THROTTLE
Figure 6-3. – Throttle Positions
4. If no movement is seen in Step 3 remove the control panel
cover. Verify the six pin connector on the printed circuit board is
seated properly, remove the connector and then replace it and
test again. Verify the switches are correctly set. See Figure 4-1
on Page 16 for positioning.
Page 40
THROTTLE
CLOSED THROTTLE
5. If problem continues remove six pin connector from printed cir-
cuit board. Set Volt meter to measure ohms. Carefully measure
from the end of the six pin harness as follows:
Figure 6-4. – Six Pin Connector Wire Colors
NOTE: Press down with the meter leads on the
connectors exposed terminals, do not probe into
the connector.
a. Connect one meter lead to Red, connect the
remaining test lead to Orange, approximately 10
ohms should be measured.
b. Connect one meter lead to Red, connect the
remaining test lead to Yellow, approximately 10
ohms should be measured.
c. Connect one meter lead to Red, connect the
remaining test lead to Brown, approximately 10
ohms should be measured.
d. Connect one meter lead to Red, connect the
remaining test lead to Black, approximately 10
ohms should be measured.
e. Connect one meter lead to Red, connect the
remaining test to the stepper motor case. No
resistance should be measured INFINITY or
Open"
See Figure 6-4.
6. Set a voltmeter to measure DC voltage.
7. Connect the positive meter test lead to Wire 15B at Terminal
Block 1 (TB1). Connect the negative meter test lead to ground.
See Figure 6-5. Place the Start-Run-Stop Switch (SW1) to
START. 12 VDC should be measured. If voltage was measured
proceed to Step 8. If voltage was not measured, proceed to
"RESULTS".
8. Set a voltmeter to measure resistance.
9. Disconnect the J2 connector from the printed circuit board.
Connect one meter test lead to Pin Location J2-1 (Wire 15B.
Connect the other meter test lead to Wire 15B at Terminal
Block 1 (TB1). See Figure 6-6. Continuity should be measured.
BLACK
BROWN
ORANGE
YELLOW
RED
EMPTY
Advertisement
Table of Contents
Troubleshooting
