Off-Vehicle Testing; Neutral Safety Switch Test; No-Load Current Test - Jeep 1987 Wrangler Workshop Manual

ELECTRICAL
STARTING SYSTEM - MOTORCRAFT (6-Cyl. Engine)
NOTE: Do not consider the initial voltage when
the engine first starts rotating. A very hot or very
cold engine may cause an excessive voltage
drop for the first few revolutions. Note the
voltage after the starter motor has obtained its
maximum RPM.
Turn the remote control starter switch O F F .
Turn the load control knob toward I N C R E A S E
(clockwise) until the indicated voltage is exactly
the same as it was when the starter motor was
rotating the engine. Switch the meter to the AMP
position.
Observe the current on the ammeter scale. This
is the current flowing through the starter motor
high current circuit under full-load conditions. If
the current flow is not within 180-220 amperes
for six-cylinder engines at room temperature,
approximately 21 °C (TOT), remove the starter
motor from the engine for bench testing.
Neutral Safety
Switch
Test
Remove the wire connector from the switch and
test the continuity between the center terminal
pin and the transmission c a s e . Continuity
s h o u l d e x i s t only w h e n the a u t o m a t i c
transmission is in the PARK or N E U T R A L
position.
NOTE: Check the linkage adjustment before
replacing the switch.
OFF-VEHICLE TESTING
No-Load Current
Test
The starter motor no-load current test will
indicate faults s u c h a s open or shorted
windings, worn bushings (rubbing armature) or
a bent armature shaft.
NOTE: The tester load control knob must be in
the full D E C R E A S E (extreme counterclockwise)
position.
Operate the starter motor with the test
equipment connected as illustrated. Note the
voltage.
AMP,
V O L T S
S E E
I.S.
N
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