2.
Wiggle engine wiring harness while observing
voltmeter. Meter should indicate approximate
battery voltage and should not vary. If no reading
is obtained, or if reading varies, check alternator
output circuit for loose or dirty connections or
damaged wiring.
If voltmeter now indicates approximate battery
voltage, voltage regulator is defective and must
be replaced. If no voltage is indicated, check ex-
citation circuit for loose or dirty connections or
damaged wiring.
4.
5.
If reading is between .75 and 1.1 volts, rotor field
circuit probably is shorted or grounded. Disas-
semble alternator and test rotor as outlined under
“Alternator Repair,” following.
d
If reading is between 6.0 and 7.0 volts, rotor field
circuit probably is open. Remove regulator and
inspect for worn brushes or dirty slip rings. Re-
place brushes if less than 1/4 in. (6 mm) long. If
brushes and slip rings are in good condition, dis-
assemble and perform rotor test as outlined un-
der “Component Testing - Rotor” following.
a
TEST 1
TEST 2
e
d
c
b
72784
e
a - Output Wire - ORANGE
b - Excitation Wire - PURPLE
c - Sensing Wire - RED/PURPLE
d - Voltmeter (0-20 Volts)
e - Ground
b
c
EXCITATION CIRCUIT
a
1.
2.
3.
Connect positive (+) voltmeter lead to tie strap
terminal on alternator and negative (–) lead to a
ground terminal on alternator (Test 1).
72785
a - Excitation Wire - PURPLE
b - Sensing Wire - RED/PURPLE
c - Tie Bar
d - Voltmeter (0-20 Volts)
e - Ground
Turn ignition switch to ON position and note volt-
meter reading. Reading should be 1.3 to 2.5
volts.
SENSING CIRCUIT
If no reading is obtained, an opening exists in al-
ternator excitation lead or in excitation circuit of
regulator. Unplug PURPLE lead from regulator.
Connect positive voltmeter lead to PURPLE lead
and negative voltmeter leads to ground (Test 2).
1.
Unplug RED/PURPLE lead from voltage regula-
tor.
Index
90-823224--2 796
CHARGING SYSTEM - 4C-5
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1993, 1994, 1995, 1996, 1997 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(4 votes, average: 4.5 out of 5)
Marine readers have rated 1993 1997 Mercury-MerCruiser GM V8 454 CID 7.4L and 502 CID 8.2L Marine Engines Service Manual Number 16 4.5 out of 5.0 based on 4 product reviews. Hugely helpful service manual! Perfect. Thank you!
Manuals are all Important for Technician
This book is invaluable if you do your own repairs. Great book.
Could not find a copy until a search brought me here.
Excellent print.
Thank you