Comprobar el sistema de carga de Harley-Davidson: diagnóstico eléctrico fácil y rápido

Very often, especially on winter dates or when for other reasons we roll less than usual with our motorcycle, we listen to that sinister noise from the shaft of the starter engine: "Tac-tac-tac-trrr". It is then that we realize that the battery is not at its best, probably for 2 fundamental causes: the battery is reaching the end of its useful life or the load system does not work correctly.

El sistema de carga
In this article we will focus on the motorcycle load system, which "manufactures" the electricity that the vehicle needs to circulate feeding its electrical systems (ignition, lighting, sensors, accessories ...) and creating a small current “extra“ ”To load the battery, which will be used later during start.

The fundamental components of the load system are, apart from the battery:

• The alternator

Composed in turn by the rotor (magnets that turn moved by the crankshaft)

and the stator (a fixed winding).

This device generates electric current when the rotor magnets revolve around the stator winding, creating an induced current (there is no physical contact between the two elements, it is generated through variations in the magnetic field). The current obtained is alternate (such as the one used in homes) and will be more voltage the faster the engine turns.

• The regulator-gratifier

This device receives the alternating current that comes from the alternator and makes it a direct current (with positive and negative).

Once rectified (this is what this process is called) the regulator sends this current to the battery, but only the one that needs, discarding excess current and not allowing the load voltage to be greater than 15V, which could damage the battery or electronic systems.

Checking the system
When verifying the loading system it is convenient to follow a series of basic steps that will help us determine if any of the components is not working properly. For these tests we will need a Multimeter.

• Battery and connections

It is fundamental before performing any other test that the battery is fully charged (about 12.6v or more, if we will not load it until this voltage is reached) and the connections of the terminals properly tightened, since they usually loosen up With vibrations. To this test we must add the visual inspection of all cables, relays, fuses and connections, in case we observe any liquid leak from the battery itself, peeled or burned cables, etc.

• Alternator

We will check the alternator's current output, to perform this task we will unplug the output connector (check your motorcycle workshop manual) and connect the multimeter test tips at that alternator output.

We put the meter in alternate voltage measurement mode, then we start the engine.

The generated voltage should be 18-20V per 1000 rpm, again we recommend you consult the manual of your year and model to verify this data.
If the output voltage is not correct, we will turn off the engine and without disconnecting the multimeter tips we will change to resistance measurement, the reading should be 0.1-0.5 ohms. We will take one of the 2 points and touch the engine block with it, in this case the reading should be "infinite." We repeat this last test with the other connector.
If these tests are correct but the alternating current of exit is still insufficient, it is likely that the problem resided in the rotor magnets, if any of the tests fails the cause will be in the stator.

• Regulator-Rectifier

When all the tests performed at the alternator are correct, it is necessary to suspect in a regulator failure. The easiest way to check this device is to start the motorcycle (remember to plug the connector that we release in the previous step) and measure directly on the battery terminals (this time with the multimeter in continuous voltage measurement). The voltage should be about 12.8-13V to the idle, and when we accelerate above 2000 rpm it should never go from 15V.

If after this test we do not obtain the correct results, we will probably have to acquire a new regulator-gratifier. Tip: Before replacing this component, make sure that it has a good mass or connection to the chassis, many times the oxide does not work well, if that were the case clean the connections well and perform the test again.

Conclusion
Although a priori may seem a complex operation, the realization of these tests will only occupy us a few minutes and will allow us to know quite precision if the load system of our motorcycle operates correctly.
It is essential to rely with the data and tests of the workshop manual for each year and model and know the basic operation of the multimeter that we are using, in this way we can make an easy, fast and precise diagnosis.

Frank Burguera

#mecanicaharley