Sometimes before the motorist raises the question of the validation of the generator of your car. After all, it is very important to prevent and to eliminate possible disruption, which may lead to failure of the battery and starting problems of the engine. The ideal option would be to entrust this work to a specialist, but if this is not possible, you can check the alternator myself at home, the main thing is to have a multimeter.

How to check the alternator without removing from car



In this case, you can check the alternator and charging relay. You need to connect a multimeter to the battery and measure the voltage in different modes in the condition of the engine. You need to give the load on the electrics: turn on/off lights, press on the gas pedal, turn on the oven and so on. If experimenting in this way, you will notice that the voltage keeps in the range of 14-14,2 Volts, we can safely say that with the alternator and the relay charging all right. If there are jumps more than 0.5-1 Volt – are faulty.

How else can you test the generator



First, check the belt tension: sometimes it's his weakness. Dismantling the generator at home, you should check the rotor. For this you need to find out what is the resistance between the slip rings of the stator. If these indicators does not exceed 5-10 Ohms, all right, if this figure is higher – perhaps where there was a breakage in the windings. Then with a multimeter you need to check the breakdown of each ring to ground. If the resistance between the rotor and each ring there is something about the breakdown can not speak, if there is a breakout. If such failure to repair the generator at home is impossible.

To check the diode bridge just. As is known, consists of 6 diodes, three positive and three negative. Disconnect all wiring from the plates with diodes and test: attach probes to the pins of the diode, and then to repeat the experiment by swapping them. In one position, you should hear a beep and the other not. If the squeak is audible in both directions, we are talking about the hole for the diode, so will have to change. But without enough experience it's hard to do, so you'll have to change the whole diode plate.

The stator you need to inspect – no Podgorny and damage the windings should not be. After you need to ring the coil with a multimeter. As for the bearings, nothing should interfere with their free rotation: there should be noise and backlash. The brushes should protrude from edge of only 5 mm. Chips, jamming and backlash is eliminated. If there are any deviations it is better to replace.