WORKSHOP MANUAL
MPV 320W / 520W
Chapter
7 - ELECTRICAL SYSTEM
EDITION
2017
PAGE
61 /
64
7.3 FUNCTIONAL CHECKS
7.3.1 General system checks
Make sure all switches are in the correct
ignition position: :
1) PTO disengaged;
2) Hydrostatic transmission in “neutral”;
3) Operator seated.
4) Parking brake engaged.
If there is no voltage supply to the battery to start the engine, perform the checks as follows.
• Phase 1
Check the battery. Use a voltmeter to check the correct voltage. Replace the battery if necessary
and/or charge to the correct level.
• Phase 2
Use a voltmeter to check for battery voltage on terminal (30) on the rear side of the ignition switch
in the «OFF» position. If there is no battery voltage on terminal (30), check the battery connection
and the fuse on the red wire.
• Phase 3
With the ignition switch in the «RUN» position, check if the battery voltage is transferred from ter-
minal (30) to terminal (15/54).
• Phase 4
With the ignition switch in the «START» position, the battery voltage is transferred from terminal
S2 to supply terminal of the contractor R8 .
• Checking the clutch of the PTO.
Remove the clutch connectors. Check the coil resistance of the clutch with a multimeter to see if
the coil is working fine. The clutch needs to have the coil resistance of 2,53 ±5% ohm. The coil is
defective if the measured resistance is higher or non-existent.
7.3.2 Checking the components
• Clutch
The resistance of the coil has to be 2,53 ±5% ohm. If the coil is defective, the resistance will either
be higher or non-existent.
• Ignition switch test.
Check the battery voltage in the «OFF» position, test for voltage at terminal 30. There must be no
voltage on terminal 51/54.
With the ignition switch in the «RUN» position, test for battery voltage at terminal 51/54.
50
87
86
30
85
87A
87
86
30
85
87A
1
2
1
2
30
15/54
50
30
15/54
50
30
15/54
BK
1
2
1
2
21
22
13
14
21
22
13
14
OFF
RUN
START