Lull 944E-42 Service Manual - Manual (Page 544)

Electrical System
9.34 Model 644E-42/944E-42 Rev. 6/04
7. To test the operation of the relays, connect a 12-volt
DC positive lead to the positive terminal (1 or 6).
Connect the negative lead to the mounting
bracket or negative post (2 or 7), listening for a
“click” sound as the contacts close. Replace the
relay if the contacts do not close.
8. When reassembling the relays to the mounting
bracket, torque the relay mounting hardware (3 or 8)
to 5 - 9 lb-ft (7 - 12,5 Nm).
9. When reassembling the wires to the relay, torque the
nuts (4 or 9) to a maximum of 95 lb-in (11 Nm).
Torque the other nuts (5 or 10), to a maximum of
40 lb-in (4,5 Nm).
10. If the vehicle has dual batteries, connect both
negative battery cables (6 and 7) to both batteries.
Connect the lower negative battery cable (6) to the
negative (-) terminal on the lower battery (8). Swing
the upper battery box (9) in and make sure that the lip
(10) on the upper battery box slides below the knob
(11). Secure in place with the knob (11).
11. Close and lock the engine cover.
Testing Diodes
To test diodes in the electrical system, set the DMM dial
on R x1 setting and connect one lead to each side
(12 and 13) of the diode. Note the reading on the DMM.
Reverse the leads and note reading. The DMM should
indicate a high or infinite resistance (no meter movement)
when connected one way and a low reading when
connected to the other. If both readings are high or
infinite, the diode is open. If both readings are low, the
diode is shorted. Repeat test on remaining diodes. If any
diodes are shorted or open, replace the diode board (14).
Note the orientation of the board when removing it for
replacement. Replace diode board in the same
orientation as it was when it was removed.
MU0511
1
2 3
4
5
MU5460
6
7
8
9
10
MU0650
6
7
8
11
10
9
12
13
MU6020
14