Thermo King KD-II SR, Manual

Page: 60 / 182

Electrical Maintenance (Rev. 04/03)
46
NOTE: Units manufactured with CYCLE-SENTRY and
alternators with integral regulators MUST use replace-
ment alternators with integral regulators.
CAUTION: “Full Fielding” alternators with the
integral regulator is accomplished by installing a
jumper from terminal F2 to ground. Attempting to full-
field the alternator by applying battery voltage to terminal
F2 will cause regulator failure.
Charging System Diagnostic Procedures
Complete the following checkout procedure before replac-
ing the voltage regulator or the alternator.
1. With the unit switch OFF, attach a voltmeter to terminal
SENSE and the alternator chassis. Voltmeter should
indicate battery voltage.
2. With the unit switch ON, attach a voltmeter to terminal
EXC and the alternator chassis. Voltmeter should indi-
cate battery voltage.
3. To determine whether the alternator or regulator is
faulty, attach a test lead between terminal F2 and
chassis ground. Run the engine on high speed.
CAUTION: Never apply battery voltage to
terminal F2.
a. Full alternator output indicates the alternator is
good but the voltage regulator needs replacement.
b. If there is LOW or NO output, the alternator is
probably faulty. However, the following items are
potential causes for not charging.
—
Check the alternator brushes
—
Check the 2A circuit from the alternator to the
battery
— Properly tension the alternator belt
—
Check the battery cable connections and the
alternator ground. They must be clean and
tight.
— The battery must be in good condition and must
accept a charge.
—
Check for excessive or unusual amperage draw
by the unit control circuits.
NOTE: A loss of battery voltage to either terminal EXC or
terminal SENSE will cause the alternator to stop
charging.
EXCESSIVE VOLTAGE OUTPUT
12V ALTERNATORS WITH INTERNAL
REGULAR SETTING
When a Thermo King unit is installed on a truck, it is often
connected to a truck battery. When both the Thermo King
unit and the truck engine are running on the truck battery,
the charging system with the higher voltage may automati-
cally turn off the charging system with the lower voltage
output.
If it is determined that the Thermo King regulator setting is
higher than the truck charging system or the batteries are
consuming more water than normal the following solution
may help solve the problem. Remove the wire labeled
SENSE and tape off. Add a jumper wire from 2A to the
SENSE terminal on the back of the alternator. This should
reduce the voltage to the battery by 0.2 to 0.3 of a volt.
BATTERY
Inspect and clean the battery terminals during scheduled
maintenance inspections. A dead or low battery can be the
cause of an LED or ammeter (optional) indicating discharge
due to lack of initial excitation of the alternator