Troubleshooting Tests
(Alternator on Engine)
!
WARNING
Be sure that engine compartment is well-venti-
lated and that there are no gasoline vapors pres-
ent (during the test) to prevent the possibility of
an explosion and/or a fire, should a spark occur.
Use the following tests in conjunction with the “Trou-
bleshooting” in Section 1. Before proceeding with the
tests, however, perform the following checks to elimi-
nate possible problem areas. Also observe “Precau-
tions,” preceding, to prevent damage to alternator
system.
ALTERNATOR OUTPUT TEST
1.
Connect positive (+) voltmeter lead to alternator
output terminal (orange wire) and negative (–)
lead to a ground terminal on alternator. With en-
gine running about 1500 RPM and all accesso-
ries turned on, voltage should be between
13.8-14.8.
1.
If problem is an undercharged battery, check to
ensurethatunderchargedconditionhasnotbeen
caused by excessive accessory current draw or
by accessories which have accidentally been left
on. Also, check that undercharged condition has
not been caused by running engine at too low a
speed for extended periods of time.
2.
If voltage output does not fall within specifica-
tions, alternator should be tested for probable
cause and disassembled for repair.
2.
Check physical condition and state of charge of
battery, as outlined in “Battery - Storage” in Sec-
tion 4A. Battery MUST BE at least 75% (1.230
specific gravity) of fully charged to obtain valid re-
sults in the following tests. If not, charge battery
before testing system.
b
3.
4.
Inspect entire alternator system wiring for de-
fects. Check all connections for tightness and
cleanliness, particularly battery cable clamps
and battery terminals.
Check alternator drive belt for excessive wear,
cracks, fraying and glazed surfaces and replace
if necessary. Also, check drive belt tension and
adjust if necessary, as outlined under “Drive Belt
Tension Adjustment.”
c
d
a
e
Circuitry Test
73081
Perform the following tests, using a 0-20 volt DC volt-
meter, to check that all of the circuits between the al-
ternator and the other components within the alterna-
tor system are in good condition.
a - Output Wire (ORANGE)
b - Excitation Wire (PURPLE)
c - Sensing Wire (RED / PURPLE)
d - Voltmeter
e - Ground
Index
4C-22 - CHARGING SYSTEM
90-823224--2 796
| 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.
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