The generator rotor 94.3701 is driven by a V-ribbed belt from the engine crankshaft pulley (on parts of VAZ-2111 engines - from the damper).
Technical characteristics of the generator 94.3701
- Maximum output current at 13 V and 5000 min-1, A…..80
- Limits of regulated voltage, V…..13.2–14.7
- Gear ratio engine-generator…..1:2.4
- Capacitor capacitance, uF…..2.2±20%
Generator 94.3701: 1 - casing; 2 - output «B+» to connect consumers; 3 - noise suppression capacitor; 4 - common output of additional diodes (joins the conclusion «D+» voltage regulator); 5 - holder of positive diodes of the rectifier unit; 6 - holder of negative diodes of the rectifier unit; 7 - stator winding leads; 8 - voltage regulator; 9 - brush holder; 10 - back cover; 11 - front cover; 12 - stator; 13 - stator winding; 14 - distance ring; 15 - washer; 16 - conical washer; 17 - pulley; 18 - nut; 19 - rotor shaft; 20 - front bearing of the rotor shaft; 21 - beak-shaped pole pieces of the rotor; 22 - rotor winding; 23 - bushing; 24 - coupling screw; 25 - rear rotor bearing; 26 - bearing sleeve; 27 - contact rings; 28 - negative diode; 29 - positive diode; 30 - additional diode; 31 - output «D» (common output of additional diodes).
Stator 12 (see fig. higher) and covers 10 and 11 are tightened with four bolts. The shaft 19 of the rotor rotates in bearings 20 and 25, which are installed in the covers. The rear bearing of the generator is pressed onto the rotor shaft and pressed by the rear cover 10 through a plastic sleeve. The front bearing 20 is rolled into the front cover 11 and can only be replaced as an assembly with it. The inner race of the front bearing 20, together with the distance ring 14 and the washer, is clamped by a nut between the pulley and the rotor shaft. The back of the generator is covered with a plastic casing 1.
The generator stator is equipped with a three-phase winding 13, made according to the scheme «star» (phase windings have a common point), the other outputs of the phase windings are connected to a rectifier bridge consisting of six silicon diodes. Diodes of only one polarity are located in the holders. Holders 5 and 6 of positive and negative diodes, respectively, form a rectifier unit, which is fixed on the rear cover 10 of the generator under a plastic casing 1. Three additional diodes 30 are installed on one of the holders, through which voltage is supplied to the excitation winding of the generator after starting the engine.
The excitation winding is located on the generator rotor. The excitation winding leads are soldered to two copper slip rings 27 mounted on the rotor shaft. Power is supplied to the excitation winding through two contact brushes and slip rings. Contact brushes are located in the brush holder 9, combined in one housing with the voltage regulator 8. The housing of the voltage regulator is non-separable, in case of failure it is replaced.
To protect the on-board network from power surges during operation engine management systems and to reduce radio interference between the terminals of the positive and negative diodes, an interference suppression capacitor 3 with a capacity of (2,2±0,004) uF located on the rectifier block.
The wiring diagram of the 94.3701 generator system is shown in the figure:
Generator connection diagram 94.3701: 1 - rechargeable battery; 2 - generator; 3 - mounting block; 4 - a control lamp for charging the battery, located in the instrument cluster; 5 - switch (lock) ignition
The current to excite the generator when the ignition is turned on is supplied to the output «D+» regulator (conclusion «D» generator) through the control lamp 4 located in the instrument cluster. When the ignition is turned on, the lamp should be on, after starting the engine it should go out if the generator is working. A bright or dimly lit lamp indicates a malfunction.
Warnings! The negative battery terminal must always be connected to «weight», and positive - with the conclusion «B+» generator. An erroneous reverse connection of the battery will immediately cause an increased current to flow through the alternator diodes, as a result they will be damaged.
It is not allowed to operate the generator with the battery disconnected - this can damage the generator voltage regulator and the electronic devices of the vehicle's on-board network.
It is forbidden to check the operability of the generator «for a spark» even a momentary output connection «B+» generator with «weight». Significant current will flow through the valves and they will be damaged. You can only check the generator with an ammeter and a voltmeter.
It is not allowed to check the diodes of the rectifier unit of the generator with a voltage of more than 12 V or with a megohmmeter, as it has a voltage too high for the diodes and they will be broken during the test (a short circuit will occur).
It is forbidden to check the car's electrical wiring with a megohmmeter or a lamp powered by a voltage of more than 12 V. If such a check is necessary, then first disconnect the wires from the generator.
It is necessary to check the insulation resistance of the stator winding with increased voltage only at the stand and always with the leads of the phase windings disconnected from the diodes.
When welding components and parts of the car body, disconnect the wires from all the terminals of the generator and the battery terminals.
Helpful Hints: If the alternator belt broke on the way, and you forgot the spare at home, a 20 mm wide ring cut from an old car inner tube can temporarily replace it.
To reduce current consumption when driving a vehicle with a faulty alternator, turn off the radio, secondary lights, heater fan, defroster, etc., if possible.