Thermo King T-1000R, Maintenance Manual

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Electrical Maintenance 8-2
ALTERNATOR CHARGING SYSTEM DIAGNOSTIC PROCEDURES
General Information
Poor charging performance may not be caused by a bad alternator. The following conditions can cause improper battery
charging, even with a good alternator.
• A problem may exist in the 2A output circuit from the alternator to the battery. Check for an open 2A circuit, loose
connections, defective battery cables or dirty battery terminals.
• The battery must be in good condition and capable of accepting a charge. Check for a damaged battery, correct electrolyte
level, and loose or corroded connections.
• The alternator charging output will be low if the alternator belt or pulleys are defective or the belt is not properly adjusted. Be
sure the belt is not loose or cracked and the pulleys are the correct size and in good condition.
• The excitation circuit (EXC circuit) must supply voltage to the excite terminal of the alternator.
• The sense circuit (SENSE circuit) must supply voltage to the sense terminal of the alternator.
• The alternator must be properly grounded.
• The unit control circuits or installed accessories may be drawing excessive current.
• An overcharged battery is usually caused by a defective voltage regulator.
Alternator Identification
• These units use Thermo King Alternators (see below), which are painted black.
1. B+ Terminal (Positive Output - 2A Wire) 5. F2 Terminal (Do Not Ground)
2. B- Terminal (Negative Ground - CH Wire) 6. Voltage Regulator and Brush Assembly
3. S Terminal (Regulator Sense - 2 Wire) 7. W Terminal (AC Output)
4. L Terminal (Regulator Excite - 7K Wire)
Thermo King Alternator Terminal and Component Locations
1
7
3
4
5
2
6