To check the generator at home, you will need a multimeter. You can independently check the belt tension, charging relay, diode bridge, stator, bearings and brushes.
Sometimes a car enthusiast is faced with the question of checking the generator of his car. After all, it is very important to timely warn and eliminate possible malfunctions that can lead to failure of the battery and problems with starting the engine. The ideal option would be to entrust this matter to a specialist, but if this is not possible, you can check the generator yourself at home, the main thing is to have a multimeter available.
How to check the generator without removing from the car
In this case, you can check the generator and the charging relay. It is necessary to connect a multimeter to the battery and measure the voltage in different modes with the engine running. To do this, you need to give an electrical load: turn on / off the headlights, press the gas pedal, turn on the stove, and so on. If, experimenting in this way, you can see that the voltage is kept within 14-14, 2 Volts, then we can safely say that everything is in order with the generator and the charging relay. If there are jumps of more than 0.5-1 Volts, there are malfunctions.
How else can you test the generator
First, check the belt tension: sometimes it's all about loosening. Having disassembled the generator at home, it is worth checking the rotor. To do this, you need to find out what is the resistance between the stator slip rings. If these indicators do not exceed 5-10 ohms, then everything is in order, if this figure is higher, it is possible that there was a break in the windings somewhere. Next, using a multimeter, you need to check the breakdown of each ring to ground. If there is resistance between the rotor and each ring, then there is no need to talk about breakdown, if there is no resistance, then there is a breakdown. With such a breakdown, it is impossible to repair the generator at home.
It is easy to check the diode bridge. As you know, it includes 6 diodes - three positive and three negative. It is necessary to disconnect all the leads from the plates with the diodes and conduct a test: attach the probes to the diode leads, and then repeat the experiment, swapping them. An audible signal should be heard in one position, and not in the other. If a squeak is heard in both directions, we are talking about a breakdown in the diode, which means you will have to change it. But without sufficient experience, this is difficult to do, so you have to change the entire diode plate.
The stator must be carefully inspected - there should be no burning or damage to the winding. Then you need to ring the winding with a multimeter. As for the bearings, nothing should interfere with their free rotation: there should be no noise and backlash. The brushes should only protrude 5 mm beyond the edges. Chips, galling and backlash are excluded. If there are any deviations, it is better to replace it.
