Thermo King SB-190 30, Manual

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Electrical Maintenance (Rev. 12/03)
35
BATTERY (DEALER SUPPLIED)
NOTE: The unit On/Off switch must be placed in the OFF
position before connecting or disconnecting the battery
terminals.
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 THERMOGUARD
µ
P-VI Microprocessor Controller Diagnosis Manual
TK 50566 for a complete list of the size and function of the
fuses.
• Fuse F3 (15 amp) protects the circuit that provides
power to defrost relay and the damper.
• Fuse F9 (40 amp) protects the main control power cir-
cuit.
• Fuse F18 (15 amp) protects the circuit that provides
power to the throttle solenoid.
• Fuse 21 (25 amp) protects the circuit that provides
power to the On/Off switch.
• A number of 2 and 5 amp fuses protect microprocessor
circuits, control relay circuits, remote light circuits, and
various components.
FUSE LINK
The fuse link is located in the positive battery cable. The
fuse link protects the electric 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. Replace the fuse link by
replacing the positive battery cable.
Relay Board
ARA165