Service Manual

Part Numbers
28-7890, 95-0659
Purpose
The module monitors the status of the safety switches and prevents spark
if an “unsafe” condition is encountered.
How It Works
The module “steals” a small amount of current from the ignition coil
primary (through the kill wire.) It sends current through the orange and
yellow wires to monitor the status of the safety switches. If EITHER of the
following two conditions are met, the module will allow spark (by not
grounding the kill wire).
1. There is continuity from the orange to the yellow wire through the
transmission and deck switches.
2. The orange wire is grounded through the seat switch.
If both circuits are open, the module “connects” the light blue kill wire to
ground. Note: There is no time delay in this module.
Testing
Caution: When using jumpers to simulate a safe condition, be sure that
the transmission and PTO lever are disengaged before starting.
The following steps assume your unit does not produce spark. (If the unit
runs in an unsafe mode, check to ensure that the module has a good
ground to the chassis and that the kill wire is not broken.)
1. Disconnect the module from the wiring harness. Jump from the light
blue wire on the module, to the light blue wire on the harness. This
allows the module to control spark. Verify now that the unit will not
produce spark when attempting to start.
2. Simulate a safe deck and transmission circuit by jumping across the
yellow and orange wires. The unit should now produce spark.
3. Disconnect the jumper from step 2 and simulate an operator on the
seat by connecting a jumper from the orange wire to the chassis. The
unit should produce spark. If the module failed any of these three
tests, it should be replaced.
NOTE: We have never seen a case of two bad modules in a row. If
replacing the module doesn’t cure it, it wasn’t the module.
Module
Interlock
Glossary
GLOSSARY
3-12 Demystification Guide