Check Start-Stop Switch - Guardian Quietpact 55 Repair Manual

S S e e c c t t i i o o n n 7 7
D D I I A A G G N N O O S S T T I I C C T T E E S S T T S S
RESULTS:
1. If battery voltage is NOT indicated in Step 1, check
continuity of:
a. Wire 13 between Starter Contactor and
Starter Contactor Relay.
b. Wire 13 between Starter Contactor Relay
and 7.5 Amp Fuse (F1).
c. Wire 15 between the 7.5 Amp fuse (F1) and
the Battery Charge Rectifier.
d. Wire 15 between the Battery Charge
Rectifier and the Engine Controller Board.
Repair, reconnect or Replace bad wiring as necessary.
2. If battery voltage is indicated but engine will not crank, go to
Test 24.
3. If "Continuity" was not measured in Step 3, repair or replace
Wire 0 between the Engine Controller Circuit Board and the
Ground Terminal.
TEST 24 - CHECK START-STOP SWITCH
DISCUSSION:
Engine cranking and startup is initiated when Wire 17
from the Engine Controller board is connected to
frame ground by setting the Start-Stop Switch to
"START".
Engine shutdown occurs when circuit board Wire 18
is connected to frame ground by the Start-Stop
Switch.
Figure 7-17. – Start-Stop Switch
A defective Start-Stop Switch can result in (a) failure
to crank when the switch is set to "START", and/or (b)
failure to shut down when the switch is set to "STOP".
PROCEDURE:
For Problem 6 (Section 6), perform all steps. For
Problem 9, perform Step 1 and Step 5 ONLY.
1. Set a VOM to its "Rx1" scale and zero the meter.
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2. Inspect the ground Wire 0B, between the Start-Stop Switch
and the grounding terminal. Connect one meter test lead to
Wire 0B on SW1. Connect the other test lead to a clean frame
ground. "Continuity" should be measured.
3. Disconnect Wire 17 from its Switch terminal and connect it to
frame ground. The engine should crank.
4. Remove the 7.5 amp fuse. Disconnect Wire 18, Wire 0B and
Wire 17 from the Start-Stop Switch (SW1).
5. Connect one test lead to the center terminal of SW1. Connect
the other test lead to an outer terminal of SW1. "Infinity" should
be measured. Remove the test lead from the outer terminal of
SW1 and connect it to the opposite outer terminal. "Infinity"
should be measured.
6. Leave the test lead connected to the center terminal of SW1
from Step 5. Connect the other test lead to an outer terminal.
Depress the switch away from the terminal being tested (see
Figure 7-18). "Continuity" should be measured. Repeat the pro-
cedure with the test lead connected to the other outer terminal.
"Continuity" should be measured.
Figure 7-18. – Test 24, Step 6
RESULTS:
1. If "Continuity" is not measured in Step 2, repair, reconnect or
replace Wire 0B (between Start-Stop Switch and ground termi-
nal) as necessary.