B5.9G, B5.9LPG - Troubleshooting and Repair Manual - 013-001 Alternator

Initial Check

Remove

Pad Mount

Spool Mount

Test

Install

Pad Mount

Spool Mount

Initial Check

TOC

Check the drive belt and alternator pulley to be sure the alternator is rotating.		SMALL \| MEDIUM \| LARGE

WARNING

Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

Check the battery and all wiring connections.

Inspect the wiring for defects.

Check all connections for tightness and cleanliness, including the slip connectors at the alternator and engine compartment bulkhead, and connections at the battery.

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Remove

TOC

Pad Mount

Remove the alternator mounting capscrews.

Remove the alternator.

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Spool Mount

Remove the alternator link capscrew.		SMALL \| MEDIUM \| LARGE

Remove the alternator mounting capscrew.

Remove the alternator.

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Typical Delco Alternator Wiring System

The main function of the indicator (I) terminal is to indicate if the alternator is working correctly. Typically, an indicator light is wired to this terminal. If the alternator is not charging properly, the light turns on. Another function of the indicator (I) terminal is that it can be used to supply up to 1 amp of output at system voltage.

Relay (R) Terminal

The function of the relay (R) terminal varies. It can supply up to 4 amps of output at one-half nominal alternator voltage to power items such as a tachometer or an hour meter.

One-Wire System

This is the simplest of the wiring systems because the only wires connected to the alternator are at the battery (BAT) and ground terminals. (See Table 5.) Connecting to the R terminal and I terminal is optional.

Three-Wire System

This system requires more wiring because it has a battery (BAT) terminal, R terminal, two blade terminals identified as number 1 and number 2, and a ground terminal. Typically, in the three-wire system, the number 1 blade terminal serves as the I terminal. (See Table 5.) The advantage of the three-wire system is that it provides the same features as the one-wire system, plus remote sense. By connecting the number 2 blade terminal to the battery’s positive (+) terminal, the voltage is both sensed and regulated at the battery instead of the alternator. This eliminates the potential for voltage losses in the wiring from the alternator to the battery.

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Table 5, Typical Alternator (Delco-Remy)

Key	Terminal	Connected To
5	BAT	Battery
3	GRD*	Ground
4	R*	Charge indicator, automatic lockout system, tachometer**
1	Blade number 1*	Indicator light
2	Blade number 2	Voltage sense
6	I*	Indicator light

*Not all alternators have this feature.

**Provides voltage pulses at about one-half system voltage at a frequency of one-tenth of generator rpm.

Test

TOC

NOTE: Any multimeter reading of zero voltage indicates an open circuit.

Check for open circuits.

Turn the ignition switch to the ON position.

Connect a multimeter, Cummins Part Number 3377161, to the following locations:

Delco Alternators

Alternator “BAT” terminal to ground
Alternator blade terminal “number 1” to ground
Alternator blade terminal “number 2” to ground.

Locate and repair the open circuit.

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Connect a carbon-pile load (battery/alternator tester) across the batteries in one of the battery boxes.

Clamp an induction pickup-type ampere-hour meter around the battery cable; or use the digital multimeter, Part Number 3377161, with the clamp-on current probe, Part Number 3823574.

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WARNING

Acid is extremely dangerous and can damage the machinery and can also cause serious burns. Always provide a tank of strong soda water as a neutralizing agent when servicing the batteries. Wear goggles and protective clothing to reduce the possibility of serious personal injury.

Disconnect any cables that lead to any other battery boxes in the circuit, negative (-) cables first.

Operate the engine at high idle; and measure the alternator voltage output to the batteries with digital multimeter, Part Number 3377161. Refer to the alternator manufacturer’s specifications.

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Operate the engine at high idle and adjust the carbon-pile load-testing equipment to apply the maximum rated amperage load to the alternator. Refer to the alternator manufacturer’s specifications.

NOTE: The alternator maximum rated amperage output is normally stamped or labeled on the alternator.

Measure the alternator amperage output. Refer to the alternator manufacturer’s specifications.

If the alternator output (amps) is not within 10 percent of rated output, repair or replace the alternator. Refer to the alternator manufacturer’s instructions for repair procedures.

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WARNING

Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To avoid arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

WARNING

Shut off the engine, and remove the test equipment.

Connect all battery cables, negative (-) cable last.