Service Manual

6-20 Z Master 597 Diesel Series Service Manual
6
ELECTRICAL
Testing
If the electric PTO clutch does not engage or is suspect
as the cause of an electrical problem in the PTO circuit,
use the following troubleshooting steps to determine
whether the clutch has failed or another electrical
problem exists.
1. Disengage the PTO, set the parking brake, turn
the ignition to the “off” position and remove the
ignition key.
2. Disconnect the clutch harness from the main
harness.
3. Set the multimeter or volt/ohm meter to check
resistance (ohms).
4. Connect the meter lead wires to the clutch wires
as shown (Fig. 380).
Fig 380 DSC-2553
Fig 379 DSC-2552
The electric clutch is located on the PTO end of the
crankshaft (Fig. 379).
The electric clutch controls the engagement and
disengagement of the Power Take Off (PTO) pulley.
Purpose
ELECTRIC PTO CLUTCH
Location
The PTO clutch is composed of three major
components; the eld, the clutch plate, and the friction
plate. The clutch plate always turns with the engine.
The eld is a coil of wire wound around an iron core,
which acts like an electromagnet when power is applied.
The friction plate is the only piece that can slide inward
and outward on the crankshaft axis. It is spring loaded
away from contact with the clutch plate. When the clutch
is not energized, the clutch plate rests against the brake
material opposite the clutch plate. When energized the
friction plate is drawn into the clutch plate magnetically
and the two rotate as one component.
How It Works
Coil Resistance Measurement
5. The meter should read between 2-4 ohms
(meter readings may vary). If the reading is
above or below these readings, the eld has
failed and needs to be replaced. If the reading
falls between 2-4 ohms, measure clutch current
draw.