DIAGNOSTICS ELECTRICAL
4 - 14 3/5/97
IGNITION CIRCUIT TEST POINTS
When diagnosing an ignition problem, isolate magneto circuit from ground circuit by separating engine connector. If
engine will not start check magneto circuit first and then check ground circuit. If engine will not shut off, check
ground circuit. Remember engine is stopped by grounding ignition coil through either key switch, seat switch or the
brake switch and PTO switch.
Test Conditions:
• Ignition switch in run position • Park Brake engaged • Blade Drive Lever disengaged
• Meter positive (+) lead on
numbered test point
• Meter negative (—) lead on
engine ground
• Engine connector disconnected
Test/Check Point Normal If Not Normal
1. Engine connector 940 white
wire (wiring harness side of
connector)
Infinite resistance Check that blade drive switch
plunger is being fully depressed by
blade drive lever
Infinite resistance Check that brake switch is being
fully depressed by brake arm
Infinite resistance Check for shorted 940, 941, 942,
white wires to chassis
Infinite resistance Check for faulty ignition switch
(internal short)
Test Conditions:
• Park brake disengaged • Seat switch depressed
Test/Check Point Normal If Not Normal
2. Engine connector 940 white
wire
Infinite resistance Check for shorted 945/946 white/
black wires
Check for faulty seat switch
Test Conditions:
• Key switch in off position • Seat switch released • Brake switch released
Test/Check Point Normal If Not Normal
3. Engine connector 940 white
wire
Maximum 0.1 ohms Check for open 940/941/942 white
wires
Check for open 100/110 black wires
www.servicemanualall.com
To Next Page
Loading...
