Electrical Maintenance (Rev. 04/02)
29
BATTERY
NOTE: The PROCESSOR On-Off switch must be placed
in the OFF position before connecting or disconnecting
the battery terminals. The PROCESSOR On-Off switch is
located on the side of the control box inside the engine
compartment.
Inspect/clean the battery terminals and check the electrolyte
level during scheduled maintenance inspections. A dead
or low battery can be the cause of an ammeter indicating
discharge due to lack of initial excitation of the alternator
even after the unit has been boosted for starting. The mini-
mum specific gravity should be 1.235. Add distilled water
as necessary to maintain the proper water level.
UNIT WIRING
Inspect the unit wiring and the wire harnesses during sched-
uled maintenance inspections for loose, chaffed or broken
wires to protect against unit malfunctions due to open or
short circuits.
FUSES
A number of fuses, located on the relay board, protect vari-
ous circuits and components. The relay board is located
inside the control box. Refer to the appropriate THERMO-
GUARD Microprocessor Controller Operation & Diagnosis
Manual for a complete list of the size and function of the
fuses.
•
A 40 amp fuse (F9—#2 Circuit) protects the 2AA cir-
cuit, which is the main power circuit.
•
A 15 amp fuse (F3—Damper) protects the 29F circuit,
which supplies power to the damper solenoid.
•
A 15 amp fuse (F18—High Speed Solenoid) protects
the 7D circuit, which supplies power to the high speed
solenoid.
•
A 15 amp fuse (F21—#8F Circuit) protects the 8F cir-
cuit, which supplies power to various control relays and
components.
•
A number of 2, 3, or 5 amp fuses protect microproces-
sor circuits, control relay circuits, remote status light
circuits (optional), and various components.
Relay Board
FUSE LINK
The fuse link is located in the engine compartment near the
battery. The fuse link protects the electrical system from a
short in the 2 circuit. If the fuse link burns out, check for a
grounded 2 wire before replacing the fuse link. The fuse
link is located in the positive battery cable in late model
units. Replace this fuse link by replacing the positive battery
cable.
AEA803
Summary of Contents for SB-III 30 SR+
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Page 111: ...101 Early Model Coiled Wire Fuse Link Wiring Schematic ...
Page 112: ...102 Early Model Coiled Wire Fuse Link Wiring Diagram Page 1 of 4 ...
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Page 115: ...105 Early Model Coiled Wire Fuse Link Wiring Diagram Page 4 of 4 ...
Page 116: ...106 Late Model Fuse Link in Battery Cable Wiring Schematic ...
Page 117: ...107 Late Model Fuse Link in Battery Cable Wiring Diagram Page 1 of 4 ...
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