Service Manual

GLOSSARY
3-10
Demystifi ction
Glossary
GLOSSARY
Relay (Electric PTO)
Location
The relay is part of the wiring harness and is located
behind the fuel tank near the PTO connector
(Figure 9).
Purpose
The relay disconnects the electric PTO clutch from
ground when the PTO is engaged and the shift lever
is in reverse, stopping the blades, unless the reverse
caution mode has been activated.
How It Works
The relay is an electrically activated single pole double
throw switch.
A common terminal (E) connects the ground wire of
the PTO clutch to ground through the normally closed
contact (A). Voltage is supplied to the positive side
of the coil (D) from the A1 terminal of the keyswitch
(Figure 10).
Placing the shift lever in reverse energizes the relay
by providing a ground connection to the coil from
the reverse switch, through the module, and PTO
switch. This opens the normally closed contacts,
disconnecting the PTO clutch from ground.
Testing
1. Disconnect the relay from the harness.
2. Verify the coil resistance between terminals B and D
with a multimeter (ohms setting). Resistance should
be approximately 105 ohms. There should be
continuity between terminals A and E (Figure 10).
3. Connect multimeter (ohms setting) leads to relay
terminals E and C. Ground terminal B and apply
+12 VDC to terminal D. The relay should make
and break continuity between terminals E and C
as 12 VDC is applied and removed from terminal D
(Figure 10).
4. Connect multimeter (ohms setting) leads to relay
terminals E and A. Apply +12 VDC to terminal D.
With terminal B still grounded, the relay should
break and make continuity between terminals E and
A as 12 VDC is applied and removed from terminal
D (Figure 10).
5. Disconnect voltage source and multimeter leads
from relay terminals.
A Norm. closed contact
B Coil Negative
C Norm. open contact
D Coil Positive
E Common contact
Figure
9
relay1
A
B D
E
C
Figure
10
relay terminals1