Toro Groundsmaster 328-D, Service Manual

Page: 187 / 402

Start Enable, Run Enable, Over Temperature and Seat Delay (GM 328–D) Relays
Three (3) relays (start enable, run enable and over tem-
perature) are used on the Groundsmaster 328–D and
Groundsmaster 345 to control engine operation. The
Groundsmaster 328–D uses an additional relay (seat
delay) to allow the engine to continue to run when the
operator lifts from the seat momentarily. The relays are
attached to a bracket under the instrument panel next to
the battery. These relays are identical. Refer to electrical
schematics in Chapter 6 – Electrical System for relay
identification.
Testing
Note:
Prior to taking small resistance readings with a
digital multimeter, short the meter test leads together.
The meter will display a small resistance value (usually
0.5 ohms or less). This resistance is due to the internal
resistance of the meter and test leads. Subtract this val-
ue from the measured value of the component you are
testing.
1. Locate relay to be tested. Disconnect the machine
wire harness connector from the relay.
2. Using a multimeter (ohms setting), measure coil re-
sistance between terminals 85 and 86 (Fig. 5). Resist-
ance should be between 70 and 90 ohms.
3. Connect multimeter (ohms setting) leads to relay ter-
minals 30 and 87. Ground terminal 86 and apply +12
VDC to terminal 85. The relay should make and break
continuity between terminals 30 and 87 as +12 VDC is
applied and removed from terminal 85.
4. Disconnect voltage from terminal 85 and multimeter
lead from terminal 87.
5. Connect multimeter (ohms setting) leads to relay ter-
minals 30 and 87A. Apply +12 VDC to terminal 85. The
relay should make and break continuity between termi-
nals 30 and 87A as +12 VDC is applied and removed
from terminal 85.
6. Disconnect voltage and multimeter leads from the
relay terminals. Reconnect relay to machine wire har-
ness.
86
85
87A 87
30
86
87A
30
87
85
Figure 5
Groundsmaster 300 Series Page 6A – 5 Electrical System (Rev. G)