Leakage current in the car: how to check the tester, bulb, multimeter?

Every year, the number of options and electronic systems in the car increases. If before the battery was needed only for starting the engine, now it is still a power source for music (often with a subwoofer), recorders, non-standard on-board computers, parktronics and other parts. All of them require food. And then one day the car owner notices that the AKB has given a strong "drawdown". The reason is current leakage in the car. How to test it yourself and what can be the reason for its occurrence? You will find out about this in our today's article.

Find out the cause of the leak

According to statistics, 90 percent of leaks occur due to non-standard equipment. This is easily explainable at the cost. When buying a new car the cost of one or another option can be tens of thousands of rubles. And installing third-party parktronics or cameras (outside the dealer), you can significantly save money. In this case, their functional will remain the same. But the reason is not in the instruments, but as their connection. Often, garage installers neglect the rules for connecting wires. Instead of the terminals, twisting is used, and sometimes the system is connected even without a fuse. This not only can cause current leakage in the car (how to check it with your own hands, we will consider later), but also cause a short circuit and even a fire. Yes, the voltage of the on-board network is only 12 volts. But this does not mean that the wires can not spark, and the car - spontaneously ignite. The installation must be taken as responsibly as possible.

What is the remaining 10 percent?

In this list there are regularly installed elements (including the generator). But often problems with them arise on 150-200 thousand kilometers. Over time, dust and dirt accumulate on the terminals. Sometimes it can get water. All this is the cause of such a phenomenon as the leakage current in the car. How to test it? Everything is very simple. But first you need to prepare the tools.

Preparation for diagnosis

So, we have a leakage current in the car. How to test it? We need a key for 8 or 10, as well as a multimeter.

Multimeter Testing

First open the hood and remove the terminal from the battery. There are two of them - we need a minus one. Further we take in hands a multimeter. We set it to the "amperage" mode. How can I check the leakage current on the car with a multimeter further? Then put his test leads between the terminal and the battery contact. We carefully look at the testimony. If they are above 0.05, then there is a leak in the car. But what if there was no such device nearby? How to check the leakage current in the car without a tester? An alternative method should be used. We will describe it below.

Alternative method

If there is no tester, it does not matter. You can always find a 12-volt light bulb and a couple of turns of wires. How can I check the current leakage in the car with a light bulb? First you need to prepare it. The element itself must be two- or three-terminal. We bend the lateral part of it (it will be a "minus"), and the second we plug in the "plus". The length of the wires should be up to one meter. It is possible and more, but it is not very convenient. To prevent the "plus" and "minus" contacts on the bulb from touching each other, insulate the terminals. Next, remove the terminal and check it in the same way (only change the polarity). Put the wire in the gap between the battery and the positive terminal. If the lamp caught fire, then there is a leak in the car. The power of the light bulb should not exceed 5 watts. It is best to use a bulb. But you can not use diode elements. They are very afraid of power surges and can easily burn out. And visually notice this will not work.

Note! All the works presented in the first and second methods are performed with the ignition switched off. This is a prerequisite for diagnosis. When choosing the second method, the lamp is not connected with the "mass" to the battery - only "plus". Otherwise it will light up in any case, even if there are no leaks.

How to fix the problem?

So, we were convinced that there is a leak in the car. But what to do with this further? Now we need to find the source of the problem. It is rather difficult to do this. First open the fuse box. The essence of the test is very clear. We need to take out each of the fuses one at a time and follow the testimony of the tester. Usually, the leak disappears when the main element that is responsible for the "reserve" is dismantled. Separately, the fuses go to the radio, headlights and taillights. Therefore, the reason we are looking for in non-standard equipment. It could be an alarm.

Finding the cause of the leak is quite a painstaking task. Sometimes we have to pick out the half-hall to find that very burnt post, which creeps into "mass". But what to do - these are the circumstances. Of course, you can simplify the search. To do this, each meter of wires is cleaned and tested for resistance. But usually the cause of leaks is a cord that has been short-circuited. Its insulating shell melts and the veins are adjacent to the metal body itself (and it is known that it is responsible for the "mass").

How to avoid a problem?

Putting more powerful batteries does not make any sense. It is necessary to exclude the root of the problem. But from now on, you do not need to ignore the wiring rules. Each wire with its polarity fits into the corrugation. The system itself must work through a fuse. It can be carried through the unit, or installed round, by connecting the terminals. Most short circuits occur precisely because of the lack of fuses. If the current is large, the sheath of wires is heated and the wires protrude outwards.

Is the leak normal?

No matter how strange it may seem, this is so (of course, within reasonable limits). Leakage is a natural process, which is even on a new car. After all, the modern machine is equipped with a multitude of systems (the same burglar alarm and computer), which will "pull" the current even at the muffled motor. Specialists identify certain figures, in which such a leak is normal. For B- and C-class cars, this figure is 40 mA per day. On minibuses it is supposed 80 mA. All that is more - equals to a malfunction. Therefore, you need to know how to check the leakage current in the car by the tester and without it. By the way, a new multimeter can be purchased for 450 rubles, which is quite acceptable.

Conclusion

So, we found out how to check the leakage current on the car with a multimeter and without it. Do not ignore this problem. After all, one day the battery will be discharged "to zero", and it will not be possible to start the car. Moreover, each deep discharge greatly reduces the capacity of the battery. If the leakage is permanent, it will not last for a year. This applies to both lead and helium batteries. Knowing how to check the current leakage in a car with a multimeter, you will save the battery capacity and will not experience startup problems.