Page 182 - CTS - Mechanic Diesel - TP

MECHANIC DIESEL - CITS

Rotate the Load Increase control to OFF.

Check each meter’s mechanical zero. Adjust, if necessary.
Connect the tester Load Leads to the battery terminals; RED to positive, BLACK to negative.
Set Volt Selector to INT 18V.
Set Test Selector to #2 CHARGING.
Adjust ammeter to read ZERO using the electrical Zero Adjust control.

Connect the clamp-on Amps Pickup around the battery ground (-) cables.
2 Turn the ignition switch to “ON” (engine not running) and read the amount of discharge on the ammeter. This
a base reading for current the alternator must supply for ignition and access ones before it can provide current
to charge the battery.
Note: The reading should be about six amps
3 Start the engine and adjust the speed to about 2000 rpm. Some models may require a different speed setting
4 After about 3-4 minutes, read the ammeter and voltmeter. Add this ammeter reading and the reading found in
step2 (engine not running).
Note: The total current should be less than 10 amps. If it is more, the alternator may still be charging
the battery. Once the battery is fully charged, you should get specified results.

The voltage should be within the specs for the alternator This is usually between 13 and 15 volts. Refer to the
appropriate repair manual. If the voltage is more than specified, replace the regulator. If the voltage is less than
specified, ground the alternator field terminal “F” and check the voltmeter reading. This bypasses the regulator,
so do not exceed the specified test speed. If the reading is still less than specified, check the alternator.
5 Remove ground from terminal

Charging With Load
6 With the engine running at specified speed, adjust the Load Increase control to obtain the highest ammeter
reading possible without causing the voltage to drop lower than 12 volts.
7 Read the ammeter.

Note: The reading should be within 10% of the alternator’s rated output. If it is less, the alternator
requires further testing or replacement.

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CITS : Automotive - Mechanic Diesel - Exercise 10.1 CITS : Automotive - Mechanic Diesel - Exercise 10.1