CHARGING SYSTEM
SERVICE MANUAL NUMBER 24
Page 4C-2
90-861327--1 OCTOBER 1999
General Precautions
The following precautions MUST BE observed when working on the alternator system.
Failure to observe these precautions may result in serious damage to the alternator or
alternator system.
1. DO NOT attempt to polarize the alternator.
2. DO NOT short across or ground any of the terminals on the alternator, except as specifi-
cally instructed in the “Troubleshooting Tests,” following.
3. NEVER disconnect the alternator output lead or battery cables when the alternator is
being driven by the engine.
4. NEVER disconnect regulator lead from alternator regulator terminal when the alternator
is being driven by the engine.
5. ALWAYS remove negative (–) battery cable from battery before working on alternator
system.
6. When installing battery, BE SURE to connect the positive (+) battery cable to the positive
(+) battery terminal and the negative (–) (grounded) battery cable to negative (–) battery
terminal.
7. If a charger or booster battery is to be used, BE SURE to connect it in parallel with exist-
ing battery (positive to positive; negative to negative).
EFI Electrical System Precautions
NOTE: All references to EFI models apply to all EFI and MPI engines.
CAUTION
Avoid damage to the EFI electrical system and components. Refer to the following
precautions when working on or around the EFI electrical harness or when adding
other electrical accessories:
•
DO NOT tap accessories into engine harness.
•
DO NOT puncture wires for testing (Probing).
•
DO NOT reverse battery leads.
•
DO NOT splice wires into harness.
•
DO NOT attempt diagnostics without proper, approved Service Tools.
Replacement Parts Warning
WARNING
Electrical, ignition and fuel system components on your MerCruiser are designed
and manufactured to comply with U.S. Coast Guard Rules and Regulations to mini-
mize risks of fire and explosion.
Use of replacement electrical, ignition or fuel system components, which do not
comply with these rules and regulations, could result in a fire or explosion hazard
and should be avoided.
IMPORTANT: Alternators are equipped with an excitation circuit. This circuit will have
approximately a 7 milliamp draw on the battery with the key in the off position. This
draw is normal.
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