Volkswagen Air Cooled 1949-1969 Repair Guide

Generator

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DESCRIPTION



Different types of generators have been used throughout the years and models. Refer to the Generator and Regulator Electrical Equipment Specifications Chart for details.

The generator warning light in the speedometer housing connects to the voltage regulator by means of terminals in the ignition switch. The warning lamp lights as soon as the ignition is turned ON, and goes out when the voltage of the generator approaches that of the battery. The warning lamp simply gives a yes-no answer to the question of whether the generator is charging or not. As such, it is potentially useful in detecting broken fan belts, because when a fan belt is broken, the generator is no longer being turned and will not charge. In type 1 or 2 models, a broken belt means that the car must not be driven until a new belt is installed. With type 3 models the fan is mounted directly on the crankshaft and the car can be driven until the battery runs out of electricity.

The generator is equipped with ball bearings that are packed with special high-temperature grease. Lubrication of the generator is not necessary under normal conditions. However, if the unit has been disassembled and/or overhauled, it is necessary to provide new lubricant for the bearings. Under no circumstances should ordinary grease be used, for it will not hold up under operating conditions.

TESTING



No-Load Voltage


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Fig. Fig. 1 Schematic for diagnosing the generator with a no-load test

In testing the no-load voltage of the generator, the cable from terminal B+ (51) at the regulator must first be disconnected. The positive lead of the voltmeter being used should be attached to terminal B+ (51) of the regulator and the negative lead of the meter grounded. With the engine running, the speed should be increased gradually until the reading of the voltmeter reaches its highest reading. If the regulator is functioning properly, the high point of the no-load voltage should be approximately 7.4 to 8.1 volts for the 6-volt system and 13.6 to 14.4 for the 12-volt system. When the engine is turned OFF, the needle of the voltmeter should drop from 6 volts (12 volts) to zero just before the engine stops.

Testing Without Regulator


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Fig. Fig. 2 Connect a voltmeter to the generator as shown to perform a generator test without the regulator

The generator can be given a very quick check without the regulator. It is most important that the duration of the test be very brief (only a few seconds) in order that the generator field windings will not be overloaded during the test.

Disconnect the two leads from the generator. Connect terminal DF of the generator to ground. Connect the positive terminal of the voltmeter to terminal D+ and the negative terminal to the generator ground. For 6 volt systems, approximately 6 volts should be generated at 1500 rpm and about 15 volts at 3000 rpm.

Installation of the regulator is the reverse of the preceding procedure, but it should be noted that the thicker cable (coming from the positive brush of the generator) must be attached at the regulator bottom to terminal + (D+). The thin cable coming from the generator field windings should be attached to the F (DF) terminal at the bottom of the regulator. If the replacement of the regulator does not correct a deficiency in the charging system, chances are that the generator itself is defective.

Inspecting the Brushes

The generator brushes should be examined periodically for wear. If they are worn to the point where they no longer extend from their holders, they should be replaced.

REMOVAL & INSTALLATION





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Fig. Fig. 3 When installing the generator on type 3 models, make sure that the mark on the generator housing is aligned with the notch on the clamping strap



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Fig. Fig. 4 When installing the generator stand on type 1 and 2 models, make sure that the oil deflector plate is installed so that the louvers are positioned as shown



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Fig. Fig. 5 To remove the generator, first remove the deck lid ...



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Fig. Fig. 6 ... then loosen the generator strap retaining bolt



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Fig. Fig. 7 Detach all wiring from the fan housing, including the spark plug cables ...



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Fig. Fig. 8 ... and remove all fan housing to cylinder head cooling tin screws



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Fig. Fig. 9 Remove the accelerator cable and guide tube from the fan housing



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Fig. Fig. 10 Lift the fan housing, generator and ignition coil off of the engine as a unit



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Fig. Fig. 11 Once removed from the engine, remove the fan tin-to-housing bolts ...



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Fig. Fig. 12 ... and separate the generator from the fan housing



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Fig. Fig. 13 If the engine is removed from the car, remove the generator mounting strap adjusting bolt ...



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Fig. Fig. 14 ... then remove the generator mounting strap



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Fig. Fig. 15 Loosen the generator-to-fan housing bolts with a 10mm wrench ...



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Fig. Fig. 16 ... then remove the 4 bolts



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Fig. Fig. 17 Lift the generator out of the fan housing



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Fig. Fig. 18 The generator stand may now be removed from the engine-remove the 4 mounting nuts ...



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Fig. Fig. 19 ... then lift the generator stand off of the crankcase . .



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Fig. Fig. 20 ... and remove the oil baffle-make sure to install the new one in the proper position

Disconnect the negative battery cable and the leads from the regulator. Remove the air cleaner and the carburetor, then take off the fan belt. Remove the retaining strap from the generator. Remove the cooling air thermostat. Remove hot air hoses from the fan housing, take out the fan housing screws and lift it off the housing. After removing the fan housing screws, the generator can be lifted off along with the fan.

Installation is the reverse of the removal procedure.

 
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