Kohler K91 Service Manual page 80

Tro ubleshooting Guide
3
1 .25 Amp Or Amp Unreg ulated Charging System
Optional 70 Watt Lighting
NOTE : Zero ohmmeters and voltmeters on each scale to ensure accurate readings . Voltage test should be
made with engine running at 3000 RPM -no load. Battery m ust be fully charged .
Problem
1 . With engine running at 3000 RPM . measure
voltage across battery terminals using a DC
voltmeter.
Disconnect the charging lead from battery .
2 .
With engine running at 3000 RPM . measure
voltage from charging lead to ground using a
DC voltmeter .
No
Charge
To
3 . With charging lead dIsconnected from battery
and engine stopped, measure resistance from
Battery
charging lead to ground using an ohmmeter.
Note reading.
Reverse the leads and measure resistance
again .
In one direction, the resistance should be
Infinity ohms (open circuit) . With the leads
reversed , some resistance shOUld be
measured (about midscale on
4 . Cut the sleevlng on the charging lead to ex-
pose the diode connections .
Measure the resistance from the stator side of
diode to ground using an ohmmeter .
Make sure lights are not burned out .
1 .
2 . Disconnect the lighting lead from the wiring
harness.
With engine running at 3000 RPM . measure
voltage from lighting lead to ground using an
No
AC voltmeter .
lights
3 . With engine stopped , measure the resistance
of stator from lighting lead to ground using an
ohmmeter.
8. 1 0
Test
Ax 1
range I .
Conclusion
1 . If voltage Is more than 1 2 . 5 volt s , charging
system Is O K .
If voltage Is 1 2 . 5 volts or less, the stator or
diode are probably faulty. Test the stator and
diode (Test 2 , 3, and 4) .
2 a . 1 .2 5 amp. If voltage Is 1 1 . 5 volts or more sta-
tor winding Is OK .
2 b . 3 amp . If voltage Is 28 volts or more , stator
winding Is O K .
I f voltage I s less than specified test stator
using an ohmmeter ( Tests 3 and 4 ) .
3 . If resistance Is low In both dIrections , t h e dIode
Is shorted. Replace the diode.
If resistance Is high In both directions , the
diode or stator winding Is open . ( Use Test 4 ) .
If resistance I s 0 . 7/1 . 3 ohms , stator winding I s
4 .
OK .
a
If resistance Is ohms , stator winding Is
shorted . Replace stator.
If resistance Is Infinity ohm s . stator winding or
lead Is open. Replace stator.
1 . Replace burned out lights.
2 . I f voltage I s 1 5 volts o r more. stator I s O K .
Check for loose connections or shorts In wiring
harness .
If voltage Is less than 1 5 volt s . test stator us-
Ing an ohmmeter ( Test 3) .
3 . If resistance I s approx. 0 . 4 ohms , stator Is
OK .
a
If resistance Is ohms , stator Is shorted. Re-
place stator.
If resistance Is Infinity ohms , stator or lighting
lead Is open . Replace stator.