1.
2.
Connect positive (+) voltmeter lead to positive
battery terminal and negative (–) voltmeter lead
to negative terminal.
4. Remove four nuts holding excitation and sensing
wires and Phillips screw. Remove regulator cover
and install wires and nuts for testing. Connect a
jumper wire from the ground stud to the brush ter-
minal on the lower right- hand side of the brush
assembly. Restart engine and gradually increase
engine speed to 1500 RPM while observing volt-
meter. DO NOT allow voltage to exceed 16 volts.
Start engine and run at fast idle until engine
reaches normal operating temperature. Adjust
engine speed to 1500-2000 RPM and observe
voltmeter for highest reading. Reading should be
between 13.9 and 14.7 volts.
5.
If a voltmeter reading of 14.5 volts or above is
now obtained, voltage regulator is faulty and
must be replaced. If voltmeter reading is below
3.
If reading is high, check for a loose or dirty regula-
tor ground lead connection. If connection is good
(and sensing circuit checked out good in “Circuit-
ry Test”), voltage regulator is faulty and must be
replaced. Be sure to disconnect battery cables
before attempting to remove regulator.
14.5
volts, inspect brushes and slip rings for
wear, dirt or damage. If brushes and slip rings are
good, alternator is faulty internally. Disassemble
alternator and test components, as outlined un-
der “Alternator Repair,” following.
a
d
e
c
b
a
d
c
b
72971
72788
a - Ground
b - Brush / Regulator Assembly
c - Brush Terminal
a - Output Wire - ORANGE
b - Excitation Wire - PURPLE
c - Sensing Wire - RED/PURPLE
d - Voltmeter (0-20 Volts)
e - Ground
d - Jumper Wire (Solder Connection Ground)
Alternator Repair
!
WARNING
Be sure that engine compartment is well-venti-
lated and that there are no gasoline vapors pres-
ent (during the next steps) to prevent the possi-
bility of an explosion and/or fire, should a spark
occur.
Removal
1.
Disconnect negative (–) battery cable from bat-
tery.
2.
Disconnect wiring harness from alternator.
!
CAUTION
3. Remove alternator brace-to-alternator attaching
bolt, washer(s) and spacer (if used).
DO NOT allow tie jumper wire to contact alterna-
tor end frame (in next step), as rectifier and diode
assembly may be damaged.
4. Loosen alternator brace-to-engine attaching bolt
and alternator mounting bolt, then pivot alterna-
tor inward and remove alternator drive belt.
5.
Remove alternator mounting bolt, washers (if
used), spacer and nut, and remove alternator.
Index
90-823224--2 796
CHARGING SYSTEM - 4C-7
| 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