If your machine doesn’t give a sign of life after the winter break, that’s still no reason to fly to the mechanic right away.
An interesting thing is that while mechanical failures most motorcyclists are able to fix on their own with more or less stress, electrical failure causes fainting and convulsions. At the outset I must point out one thing. I do not use professional nomenclature too diligently. I talk about cables, electricity and sometimes wires. I am not an electrician, so I often use mental shortcuts and simplifications.
When the lights go out
Let’s start with the so-called power failure. This most often manifests itself when trying to start the motorcycle. We turn the key and…. here are two options. In the first, nothing lights up, that is, the current is missing. In the second, it lights up, but after pressing the starter everything dims and sometimes you can hear a rattling sound. In the first option, the battery is probably only suitable for throwing away. In the second, not necessarily. Anyway, in such a case we again have two choices. We can try to start the machine “from the cables” or from “push”. These are acceptable solutions if we are not at home. At home, first of all, we should check the voltage at the battery clamps. If it is below 12 volts then we know that the battery is underperforming. If it is 12.5 V then we may have a bigger problem. But there is no need to panic. Let’s check one more thing. Let’s connect a meter to the clamps and try to start the motorcycle. If there is no voltage drop then we have a problem, and if there is then the battery has simply died and you need to buy a new one. Once in a while we get such cases in which the battery at rest shows a good voltage, the charge is at the right level, and yet the starter does not want to turn on. In the case where there is no voltage drop, this could mean a failure of the starter button, the starter relay, the starter itself, or something you would never run into in your life. The latter option occurs quite occasionally.
The deeper into the forest…
Since the situation is developing in this direction, we need to check that the various components are working. For this we need to find the starter relay. In most motorcycles, this is such a metal thing to which two thick wires, usually red in color, are screwed with two nuts. The relay can usually be found near the battery. There are two more wires going to it. The power/control one from the button on the steering wheel and the ground one. We need to check if voltage appears on one of them when the starter is pressed. If so, we keep looking. We press the starter again and check if there is voltage on the second relay screw, the one from which the wire to the starter is routed. Later, we still check if there is voltage on the starter itself on the power wire.
…the more trees
If everything is fine, it remains to check the starter itself. We check that the machine is at idle and briefly short-circuit with a thick cable the plus terminal and the screw on the starter, which is attached to the power cable. A healthy starter will turn the engine like crazy. You will ask, why is it necessary to use a thick cable? Because there are smaller voltage drops on a large cross section and you won’t burn your hands. Here a small digression. When buying starter cables, you should always check what is the diameter of the copper braid. The amount of insulation does not interest us. Following this rule, you will most likely never buy starter cables at a gas station. I’m generalizing a little, but once in a thousand you manage to come across a good product. Of course, it is best to make such a set yourself. All you need are terminals from a perennial set and two larger diameter wires. You can buy them in a wholesaler of electrical supplies or in a store with parts for “Maluchs”, that is, Fiat 126p. At the parts store, ask for the wire connecting the battery to the starter. In the “Maluch” the battery was in the front in the trunk, and the starter was in the back. Of course, the option with a wholesaler is many times cheaper, but the final choice depends on which store we have closer.
If we have checked all the components and still the motorcycle does not want to turn then it is worth cleaning all the electrical connections. Sometimes a slick tip is the culprit of the whole incident.
What if there is simply only 10V on the battery clamps, for example? The first instinct is to check if we have a charge. And very well. How to accomplish this? We connect with the engine running to the clamps. I know, I know, after all, the motorcycle can’t be started. I left out here the important issue of charging the battery or buying a new one. We buy a new one if charging doesn’t do anything. Anyway, we look at what the charging voltage is. It should be between 13.8V and 14.4V over a wide range of no-load revolutions, i.e. without any consumers such as lights or other heated manoeuvres on. When the lights are on, we should not notice too much voltage drop. In fact, with modern electronic regulators, there will be no big differences. If after turning on the lights the voltage drops significantly or the values read below 13V then we have a problem with the regulator or the alternator itself. This is easy to check.
Alternator
You need to look for the wires coming out from under the alternator lid and measure the voltage between them. There are almost always three wires, because the alternator is a three-phase AC generator. I wrote that almost always, because in older Ducati phases are two. We check the first with the second, the first with the third, the second with the third. All with the engine running, of course. The voltage should be the same every time. Its value must be checked in the service manual. In general, it should increase with rotation. If the voltage differences are significant, it means that the alternator has failed. It will be either a short circuit to ground or internal of any coil or, as it happens in my “favorite” Cowasocky (Kawasaki editor’s note) the magnets on the flywheel break off. The second case is sometimes painful. The first can be repaired.
Regulator
However, if the readings during the measurements are appropriate then this may indicate a failure of the voltage regulator. This manifests itself precisely as a lack of charging, or too much charging. Too much charging can lead to bloating and boiling the battery, as well as burning the motorcycle’s installation, and in extreme cases to fire. If you are replacing the regulator, I recommend cutting the plugs and soldering everything. This will give certainty of current flow. This is not difficult to do. From the alternator go three wires usually white or yellow. There are also three wires of the same color coming out of the regulator, plus one red and one black. These two threes need to be connected together in any configuration. The phase is the phase and that’s it. Red goes to the battery’s plus clamp, and black is ground. Most often, the old cubes are cut and there is no doubt what to connect to what.
What steals electricity?
And what if the charge is as it should be, the battery can be charged, but after a night the motorcycle refuses to cooperate? Most likely, someone is stealing “prund” from us. This someone is most often a motorcycle alarm. Recently I had a Yamaha TDM that was electrically inoperative. It turned out that in the alarm detached such … “dangle” which was probably once part of the shock sensor. This something was flying around inside the alarm housing and, depending on where it lodged at a standstill, caused short circuits leading to battery discharge. How to check if we have an unwanted draw somewhere? Plug in the meter. This time you need to set it with the dial to the A or sometimes mA position. Connect the meter between the battery terminal and the wire unscrewed from it. A small intake is possible if we have, for example, a digital display of kilometers and an engine powered by injection. However, if our machine has carburetors and an analog odometer then there should be only zeros on the meter. Of course, there are situations where short circuits are made once in a while. This, unfortunately, is a very uncomfortable situation for both the motorcycle owner and the service. Then there is only one thing to say. Let you come when it breaks down.
Electricity does not tick…
Of course, this description does not exhaust the subject. We still have motorcycles with car-type alternators, but about that another time. As you can see, if you follow the procedures, “currents” are not terrible. However, sometimes it happens, as in the case of a two-stroke engine. The fuel is there, the spark is there, and it doesn’t work. Then you need to delve more thoroughly into the theory, and sometimes just leave everything for two days and approach the subject with a fresh head.
