Alternator & Regulator GMC Typhoon I

DESCRIPTION

The CS130 and CS144 (Charging System) alternators have a high amperage output. The 130 or 144 designation is the outside diameter of the stator laminations, measured in millimeters. This alternator series also has an integral regulator but does not have a diode trio. (Scheme 1) The delta wound stator, rectifier bridge, rotor with slip rings, and brushes are similar to other alternators. A conventional fan and pulley are used. An internal fan cools the slip rings, end frame, rectifier bridge and regulator.

The CS130 alternator should not be disassembled for any reason. The alternator requires no periodic maintenance or adjustment and is serviceable only by complete replacement. The CS144, however, is serviceable. For model and alternator applications, refer to the ALTERNATOR IDENTIFICATION & OUTPUT .

Scheme 1

OPERATION

Regulator voltage varies to compensate for tempe.rature. Voltage is regulated by controlling rotor field current. The regulator switches rotor field current on and off at a fixed freque.ncy of approximately 400 cycles per second.

The regulator has 4 terminals: "P", "L", "I" and "S". (Scheme 2) The "L" terminal and/or the "I" terminal is used to turn on regulator and allows field current to flow when ignition -switch is turned to START or RUN position. The "L" terminal is connected through a charging indicator light or resistor. The "I" terminal is connected to positive battery terminal either directly or through a resistor. These terminals are often used in parallel and are connected to 2 different vehicle circuits.

The "P" terminal is connected internally to the stator and may be wired to a tachometer or other device. The "S" terminal may be used to sense voltage at another vehicle location for voltage control. If "S" terminal is not used, alternator uses an internal sensor for voltage control.

Scheme 2

BELT TENSION

BELT ADJUSTMENT SPECIFICATIONS

TROUBLE SHOOTING

Note. See TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.

ON-VEHICLE TESTING

Note. Before making electrical checks, visually inspect all terminals for clean, tight connections. Check alternator mounting bolts and drive belt tension. Ensure battery is in good condition prior to testing charging system.

Overcharged Or Undercharged Battery

1. If an overcharging condition is suspected, run engine at moderate speed. Connect voltmeter across battery terminals. If voltmeter indicates more than 16 volts, replace alternator.
2. If an undercharging condition is suspected, disconnect 4-wire connector from alternator. Turn ignition on with engine off. Connect a voltmeter between terminal "L" in wiring harness and ground. (Scheme 2) Record reading.
3. If terminal "I" is used, connect voltmeter between terminal "I" and ground. Record reading. If voltmeter reads battery voltage, circuits are okay. If voltmeter reads zero, this indicates an open circuit between terminal checked and battery. Repair as necessary.

Alternator Output Test

1. Connect an ammeter in series with wire connected to BAT terminal of alternator. (Scheme 2) Turn on all available accessories. Connect a carbon pile across battery. Operate engine at 2000 RPM. Adjust carbon pile (as required) to obtain maximum current output while maintaining 13 volts or more.
2. Ampere output must be within 15 amps of rated output. If output is not within 15 amps of rated output, replace alternator. See «ALTERNATOR IDENTIFICATION & OUTPUT»(/gmc/typhoon/i-1991-1993/remont/charging-system/#alternator-regulator).

BENCH TESTING

Note. Internal components of CS130 alternator are not serviceable. Alternator replacement is required.

Scheme 3

1. To check for ground, attach one ohmmeter lead to shaft and other lead to either slip ring. (Scheme 3) If reading is not infinity, replace rotor.
2. To test for open, attach one ohmmeter lead to each slip ring. (Scheme 3) Resistance should be low. If reading is high (infinity), replace rotor.
3. To test for short, connect battery and ammeter in series with edge of two slip rings. Reading should be 124 amps. If reading is greater than 124 amps, winding is shorted, replace rotor.
4. To test for excessive resistance, connect ohmmeter across 2 slip rings. Reading should be 2.1-2.4 ohms at 80°F (27°C). If reading is greater than 2.4 ohms, excessive resistance is present. If reading is less than 2.1 ohms, winding is shorted, replace rotor.
5. Resistance and ammeter readings will vary slightly with winding temperature changes. If alternator does not supply rated output, and rotor is okay, rectifier bridge, stator or regulator is faulty.

Stator Test (CS144)

1. To check for ground, connect one ohmmeter lead to any stator lead. Connect remaining ohmmeter lead to stator frame. Ohmmeter reading should be infinity. (Scheme 4)
2. Delco CS series alternators have delta stator windings and cannot be tested for short or open circuits with ohmmeter. A noticeable discoloration anywhere on the stator usually indicates stator failure.

Scheme 4

Note. Some digital ohmmeters cannot be used to check diodes in rectifier bridge. Consult ohmmeter manufacturer to determine ohmmeter capabilities.

Scheme 5

1. Position ohmmeter with one lead touching grounded heat sink and other lead pressed firmly against flat metal clip on one of 3 terminals. Observe reading, and reverse test lead connections. (Scheme 5)
2. If readings are same, replace rectifier bridge. A good bridge will give a high and low reading. Repeat tests for remaining terminals. There should be 6 tests altogether (2 tests at each terminal).
3. Connect test leads to insulated heat sink and one of the 3 terminals. (Scheme 5) Observe reading and reverse connections. Repeat tests for remaining terminals. There should be a total of 6 tests (2 at each terminal).
4. Testing is complete when all 12 tests have been made. If any terminals have same readings for both connections (leads reversed), replace rectifier bridge.

Regulator Test (CS144)

Regulator cannot be tested for short, open or grounded circuits. If rotor, stator and rectifier bridge are okay and alternator continues to produce greater than 16 volts or does not produce within 15 amps of rated output during alternator output test, replace regulator. See ALTERNATOR IDENTIFICATION & OUTPUT .

REMOVAL & INSTALLATION

Disconnect negative battery cable. Remove drive belt. Remove nut retaining positive battery terminal. Disconnect alternator electrical connector. Remove mounting bolts, nuts, braces and brackets. Remove other components as necessary. Remove alternator. To install, reverse removal procedure.

OVERHAUL

Note. CS130 is not serviceable. Replacement is required.

Scheme 6

1. Clamp the mounting flange of the alternator in a vise. Mark slip ring end frame and drive end frame for reassembly reference. (Scheme 6) Remove 4 through bolts. Separate rotor and drive end frame assembly from slip ring end frame.
2. Secure, but DO NOT overtighten, rotor and drive end frame assembly in vise. Remove pulley nut and washer from rotor shaft. Remove pulley, fan collar, fan and outside collar from rotor shaft. Remove drive end frame and inside collar from rotor shaft. Remove three screws and retainer from drive end frame.
3. Press front bearing from drive end frame. Using Bearing Remover (J-28509-A), remove rear bearing from rotor shaft. (Scheme 7) Remove 3 stator lead nuts and remove stator. Remove one screw from brush holder and 2 screws from regulator connector. Remove brush holder, regulator and regulator connector as an assembly from slip ring end frame. NOTE: If brush holder, regulator or regulator connector is faulty, components must be unsoldered from each other using as little heat as possible to prevent damage to regulator. (Scheme 8)
4. Remove BAT terminal nut from insulated heat sink. Remove 2 screws and washers from grounded heat sink. Remove capacitor and rectifier bridge from slip ring end frame. Remove BAT terminal from outside of slip ring end frame.

Scheme 7

Note. The following Figure is Courtesy of General Motors.

Identifying Brush Holder, Regulator & Regulator Connector Assembly Connections (Model CS144). Scheme 8

Inspection

1. Using clean solvent, wash all metal parts except voltage regulator, rectifier bridge, bearings, stator and rotor. Inspect terminal connections for corrosion and damage. Inspect alternator housing for cracks, warping and damage. Replace alternator as necessary.
2. Inspect stator windings and rotor for burned (blackened) insulation. Replace stator or rotor as necessary. Inspect stator windings for chipped insulation. Repair with insulating varnish or replace stator if damage is excessive.
3. Inspect rotor slip rings. They may be cleaned with 400 grit or finer polishing cloth while rotor is being rotated. Slip rings may be lathe turned to maximum indicator reading of .002" (.05 mm). Slip rings are not replaceable. Replace rotor if slip rings are excessively damaged. Inspect slip ring end of rotor shaft for overheating or scoring. Replace rotor as necessary.
4. Inspect front bearing for looseness, roughness and wear. Replace as necessary. Rear bearing must be replaced if alternator is disassembled.
5. Inspect brushes for wear. Replace if worn to less than 50 percent of original length. Inspect brush holder for damage. Inspect brush springs for corrosion or damage.

Reassembly

1. Install BAT terminal onto outside of slip ring end frame. Install rectifier bridge and capacitor into slip ring end frame, ensuring insulated side of capacitor is against frame. Install 2 screws and washers through grounded heat sink. Install BAT terminal nut with flat side down to insulated heat sink. NOTE: A design change in brush holder and slip ring end frame prevents early design brush holders from being installed in later design slip ring end frames. To modify brush holder, remove two locators from brush holder and file jagged edges down to level of surrounding material ensuring loose particles are kept out of brush slots.
2. Assemble brush holder, regulator and regulator connector together, crimping connections of components. (Scheme 8) Solder connections using very little heat to avoid damage to regulator. Install brush holder, regulator and regulator connector assembly into slip ring end frame, ensuring regulator connection rests against metal side of capacitor strap.
3. Install one screw into brush holder and 2 screws into regulator connector. Install brushes into brush holder. Retract brushes in brush holder and retain with pin or toothpick, ensuring pin or toothpick extends through slip ring end frame for later removal.
4. Install stator into slip ring end frame. Position 3 stator leads to 3 rectifier bridge terminals. Install and tighten 3 stator lead nuts. Install front bearing into drive end frame by pressing against outer race. Install retainer onto drive end frame using 3 screws.
5. Install NEW rear bearing onto rotor, pressing against inner race until stop is reached. Install rotor into drive end frame sliding rotor shaft through inside collar and drive end frame. Install outside collar, fan and fan collar onto rotor shaft. Install pulley, washer and pulley nut onto rotor shaft. Tighten pulley nut to 75 ft. lbs (100 N.m).
6. Assemble rotor and drive end frame assembly to slip ring end frame matching marks made during disassembly and carefully guiding rear bearing into slip ring end frame. Install and tighten 4 through bolts. Remove pin or toothpick retaining retracted brushes through slip ring end frame, enabling brushes to contact slip rings.

ALTERNATOR SPECIFICATIONS

ALTERNATOR IDENTIFICATION & OUTPUT

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• TROUBLE SHOOTING - BASIC PROCEDURES
• COMPUTER RELEARN PROCEDURES
• ALTERNATOR IDENTIFICATION & OUTPUT