TM 5-2420-231-23-1
0073
Table 1. Multiple Backhoe Operations (Pilot Controls) Do Not Function Correctly - Continued.
073
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
5. Using a digital multimeter, test for
Continuity - Proceed to Test Step 17.
Multiple Backhoe
continuity between pilot control
No Continuity - Proceed to Test Step
Operations (Pilot Controls)
wiring harness connector (WP
18.
Do Not Function Correctly -
0007, Figure 163) terminals 6 and
Continued
7. There should be no continuity.
Test Step 17. Test for Shorted Right-
Hand Tower Wiring Harness.
1. Disconnect pilot control wiring har-
ness connector (WP 0007, Figure
161) from right-hand tower wiring
harness connector (WP 0007, Fig-
ure 162).
2. Using a digital multimeter, test for
Continuity - Replace pilot controls
continuity between pilot control
wiring harness (WP 0187).
wiring harness connector (WP
Proceed to Test Step 29.
0007, Figure 161) terminals B and
No Continuity - Replace right-hand
E. There should be no continuity.
tower wiring harness (WP 0188).
Proceed to Test Step 29.
Test Step 18. Test for Faulty Pilot
Control Relay.
Using a digital multimeter, measure
Resistance 65 to 95 Ohms - Proceed
resistance between pilot control relay
to Test Step 19.
(WP 0007, Figure 168) terminals 85 and
Resistance Less Than 65 Ohms or
86. Resistance should be 65 to 95 ohms
Greater Than 95 Ohms - Replace pilot
or less.
control relay (WP 0007, Figure 168).
Proceed to Test Step 29.
Test Step 19. Test for Faulty
Pressure Reducing Solenoid Diode.
Using a digital multimeter in diode test
Continuity - Replace pressure
setting, test for continuity between
reducing solenoid diode (WP 0007,
pressure reducing solenoid diode (WP
Figure 189).
0007, Figure 189) positive lead on
No Continuity - Replace pilot control
terminal 602 and negative lead on
valve assembly (WP 0264).
terminal 30. There should be no
Proceed to Test Step 29.
continuity.
Test Step 20. Test for Faulty Pattern
Change Switch.
1. Pull control pattern switch (Figure
4, Item 1) from right-hand backhoe
tower and disconnect right-hand
backhoe tower wiring harness con-
nector (Figure 4, Item 2) from pat-
tern change switch.
2. Turn control pattern switch to posi-
tion 1 (TM 5-2420-231-10).
0073-10
