How to light a car from another car

Once the driver, sitting in his own car and turning the key in the ignition, hears only a click. The starter does not scroll, the light on the panel is not lit, and the multimedia system is silent - all this together is a consequence of a dead battery.

The reasons for this situation are many, including left for a long time included electrical appliances or short circuit wiring. If this happened away from the charger, then you need to know in advance how to light a car from another car.


  • 1 Correct diagnosis
  • 2 Step by Step Instructions
  • 3 Follow up
  • 4 Security measures

Correct diagnosis

Before using the "crocodiles" to transfer energy between cars, you need to make sure that the reason lies precisely with the battery. To do this, we will test the work of all available electrical appliances connected to the network. If the starter rotates and the engine does not start, then it is worth checking the key points where the lock can manifest itself:

  • control sensors behave incorrectly due to failure or negative external conditions (extreme temperatures, presence of fluid in the body, blocking of working parts, etc.);
  • automobile candles require replacement (burned out, damaged, etc.);
  • the condensate in the gas tank froze at extreme temperatures and blocked the passage of fuel through the system.

When these reasons are excluded, it is necessary to light from the battery of another car. At the same time it is necessary to follow certain rules.

Step-by-step instruction

Once in a difficult situation, you need to find a donor vehicle that can power your battery. The process is quite simple if you follow certain rules.

how to light a car from another car

Machines are arranged so that the metal elements do not touch each other. In this case, the connecting wires are selected in such a way that the lighting from another car does not occur when the position is taut. Provides free sagging.

In both cars, the movement is blocked by handbrake. The motors of both vehicles are jammed. It is necessary to check that the batteries would have comparable power. Electrical appliances and ignition do not turn on until the charging process is complete.

Important! All electrical consumers in the car are disconnected in order to prevent their burning at possible surges.

Stepwise Algorithm:

  • before lighting a car from another car, we are looking for a donor vehicle, which can be any passing car or a vehicle of a friend called by phone;
  • do not worry because of the lack of connecting wires, as they are often carried by many motorists in the trunk;
  • it is desirable to adjust the car by such a side in order to use wires of the minimum length;
  • in order to properly light a car from a car, you must first turn off the alarm or check it by pressing the key fob;
  • the powering machine is jammed and the hood is opened to make contact;
  • for charging, it is preferable to use contacts with spring toothed clips (crocodiles), which traditionally have a different color: black (for connecting negative charges, usually closed with caps) and red (for conjugating positive charges);
  • the basic rules for lighting from another car are to first of all connect the positive contacts between them, and it is absolutely not allowed to touch the bare end of the “+” with the “mass”
  • in the next stage, the “crocodiles” are fixed with one clip to the “minus” of the donor's battery, and the second connects to the minus of the consumer, which can be the unpainted surface of the auto block.

Important! It is not recommended to throw a negative contact from the donor directly to the "minus" battery of the consumer, as this can quickly discharge the working battery.

We remove the connecting wires from the various moving elements of the motor, capable of hooking the hinged wiring at the start. We control the reliability of fixing all four contacts. Everything must be done carefully and at a sufficient distance, since a spark may occur in the process of closing the circuit.

See also: Computer diagnostics of car errors do it yourself

Following actions

The ideal option is a situation in which such charging is carried out for 5-10 minutes. During this time interval, the planted battery will pick up enough charge for an easy start. Not everyone has the opportunity for such a pause, so you have to use a more intense version of the energy output.

The car, giving the charge, we start for a few minutes. At this time, we provide the crankshaft rotation speed up to 2000 rpm, we control it by tachometer. Turn off the engine in one car and try to start the second car, with a recharged battery. If a set of sufficient charge did not occur at the first stage, then we repeat the procedure with the donor motor started again after a 2-3 minute pause.

When the consumer battery has gained the necessary charge and allowed the engine to start, it is necessary to ensure that the manual and automatic gearbox positions the switch lever in the neutral position. Without turning off the engine, we leave the car interior to disconnect the connecting wires. This is done in the reverse order of the connection:

  • we recline the “crocodile” from the negative terminal of our battery;
  • we recline the “crocodile” from the autodonor negative terminal;
  • disconnect the "plus" from the auto donor;
  • disconnect the "plus" from the battery of the consumer.

At this time, do not turn off the work of its own motor. The correct step would be to open up the contacts including the maximum number of consumers in the car:

  • rear window heating;
  • stove;
  • dipped or front position, etc.

This step will reduce the effect of voltage drops during a power source shutdown. It is recommended to perform it in order to protect the electronics in the car.

Security measures

In some cases, use an extreme technique for a quick start. It lies in the fact that in place of the dead battery put a working battery. Next, the car starts, fold the terminals and return the discharged battery in place, connecting the contacts.

It is not recommended to do this trick on injection engines. Such voltage drops can destroy important electrical consumers. It is necessary to handle the battery as carefully as possible, since there is an acid solution inside the container. If for some reason it froze in extreme cold, it could lead to an explosion.

See also: How the generator works

Energized from a weak small car to a large transport is not worth it, because it will not provide the proper charge to the consumer. No need to light a gasoline car from a diesel, since the starting current of diesel engines is greater and can harm the gasoline engine.

It is problematic to light in frost below -20WITH. In such a situation, you should tow the car or call a tow truck. It is not necessary to light from the instituted transport on new cars in which there is a mass of electronics. Voltage drops are destructive and lead to disastrous consequences for the donor machine. On the performance of an old car, this has little effect.