7.2.4. Check of current of return of the generator

This test defines whether there corresponds current of return of the generator to nominal rate.

Preparation for check
Before the test execute the following checks and if necessary repair faulty details and units.
Check a condition of the rechargeable battery installed on the car.

NOTE
The rechargeable battery used when conducting this check has to be slightly discharged. The loading created by completely charged battery is not suitable for exact conducting this check.

Check a generator drive belt tension.
Transfer an ignition lock key to the provision of "OFF".
Disconnect a wire from the negative plug of the rechargeable battery.
Disconnect a regular wire from a conclusion "In" the generator.
Connect the ampermeter (a direct current, with a range of 0-100 And) it is consecutive between a conclusion "In" the generator and its regular wire. Make sure that the wire (–) of the ampermeter is connected to the regular wire disconnected from the generator.

NOTE
Reliably and densely fix each connection as on conclusions current of big force will move. Do not use clips (crocodile type) at connection to an electric chain.


Fig. 7.11. Scheme of check of current of return of the generator


Connect the voltmeter (with a scale of 0-20 V) between a conclusion "In" the generator and "weight". Connect (+) a voltmeter wire to a conclusion "In" the generator, and then (–) a voltmeter wire to suitable "weight" (to a body) (fig. 7.11).
Connect a control tachometer according to the instruction of the manufacturer. Connect a wire to (–) plug of the rechargeable battery.
Leave an engine cowl open.

Procedure of check
Make sure that the voltmeter shows tension of the rechargeable battery. If the voltmeter shows 0 in, then or there was a break of a chain between a conclusion "In" the generator and (-) the plug of the rechargeable battery, or the fusible insert fused, or bad connection with "weight" takes place.
Start the engine and include headlights of head light.
Turn on driving beam of headlights and install the heater electric fan switch in the provision of "HIGH", then sharply increase the frequency of rotation of a bent shaft of the engine up to 2500 min.-1 and consider the maximum value of current of return of the generator (shown by the ampermeter).

NOTE
After start of the engine charging current quickly falls. You carry out an inspection as soon as possible to manage to measure the maximum value of current of return of the generator.

Analysis of results
Indications of the ampermeter have to be above extreme admissible value. If indications of the ampermeter are lower than maximum permissible value, and at the same time the chain of a conclusion of "B" of the generator is serviceable, remove the generator from the car and make its check at the stand.
Maximum permissible value.
the generator 75 A – at least 52,5 And.
the generator 90 A – at least 63,0 And.

NOTE
The nominal force of return of the generator is beaten out on the plate attached to the generator case.
The size of current of return changes depending on load of the generator and temperatures of the case of the generator therefore the nominal force of return can be not reached. In similar cases for increase in electric loading (to discharge the rechargeable battery) turn on driving beam of headlights for some time or connect system of external lighting of other car.
The nominal rate of current of return of the generator can be not received also as a result of an overheat of the case of the generator or too high temperature of air. In such cases let's the generator be cooled and execute check repeatedly.

After completion of check of current of return of the generator gradually lower turns of a bent shaft of the engine to idling turns, then switch off ignition.
Disconnect a wire from the negative plug of the rechargeable battery.
Remove the ampermeter, the voltmeter and a control tachometer.
Connect a regular wire to a conclusion "In" the generator.
Connect a wire to the negative plug of the rechargeable battery.