How to check the high voltage wires on the car?

Most cars use high voltage wires, the task of which is to transfer electric current from the coil or ignition module to the candles. As well as other parts of the car, during operation they can fail. Electrical and electromagnetic interference arise as a result of the discrepancy between the quality of the automotive wire and the installed parameters. They have a negative effect on electronic devices, without which it is difficult to imagine modern machines. The engine is also affected by a malfunction of the electronics.

What you need to know

To eliminate the resulting interference, special protective treatment of high-voltage cables is used. There are basic rules, compliance with which guarantees the receipt of quality products:

• The supply of current must only be from the coil;
• From the tip of the candle and to the coil itself, there should be no slightest leakage;
• Low resistance;
• Resistance to sudden temperature fluctuations;
• Resistance to environmental and chemical agents.

It should be noted that the choice of cable should be in accordance with the equipment of the machine. Equally important is the regular replacement of high voltage wires , especially those that are connected to electronic systems. The occurrence of a voltage leak is possible with the slightest malfunction, because of this, the degree of toxicity of exhaust gases increases and the quality of the engine's performance deteriorates.

Causes of malfunction

Among the main breakdowns, the insufficient voltage in the spark plugs has become most widespread. It can occur for several reasons:

• Absence of contact between high-voltage cables and candles;
• Exceeding the established resistance level;
• Poor-quality insulation, conducive to voltage leakage;
• Break line under the insulating layer.

If the VAZ high voltage wires are broken, the voltage level decreases and an electromagnetic pulse occurs preventing the nominal voltage from being transmitted to the spark plug. As a result of damage, there is a disruption in the operation of the cylinders caused by slow ignition, as well as intermittent operation of the engine and improper response of important car sensors.

How to check the high voltage wires on the car

In order to identify the damaged wire, you will need a normal multimeter, which is necessary to check the ignition line. It is recommended to perform a test with unstable operation of the sensors and the motor at idle. This device allows you to determine the level of resistance and identify a damaged line.

The resistance of the cables can be different, it is selected according to the engine and the manufacturer's recommendations. If any inconsistency is revealed, the line must be replaced.

Before checking the high voltage wires with a multimeter, inspect them for chipped, melted areas and other damage. Breakage of the cable is a frequent situation, often it occurs as a result of touching the engine parts, heated to a high temperature or performing inaccurate repair work. Also, the chemical attack on the surface of chemical aggressive substances has a negative effect.

Verification stages

On the contact part of the cables there should be no traces of oxidation process and carbon deposits. Do not forget about checking for tears under the insulation layer. To identify weaknesses, you need to inspect the line with the engine running. If they are present, sparks will appear at the disconnected points. For a more accurate check, it is recommended to turn off the lighting in the garage or to work in the evening.

Before checking the cables with a multimeter, they must be removed. To reverse the installation of high voltage wires was easier, it is recommended to take each line separately and immediately fix it in the same place.

The device chooses the mode of resistance diagnostics, the optimum option will be a range of 10 kOhm. The rupture is determined by the absence of the slightest resistance in the cable. Such a product does not perform its tasks and is subject to replacement. The average cable resistance is about 5-6 kΩ.

Level of voltage

As noted earlier, the voltage directly depends on the ignition system used in the car and the brand of the car. Its value can be in the range of 30-50 kV, as a rule, this parameter is indicated on the product itself. It should be noted that the VAZ-2110 high-voltage wires, included in one set, should have a similar nominal resistance, with a difference of not more than 2 kOhm. If this parameter is exceeded, it is recommended to replace the entire set.

Features of choice

The main factor in the choice is not only the manufacturer and the brand of cables. No less attention is required by the motor model. This is due to the fact that when changing and repairing the wiring must take into account some features that depend on the manufacturer.

The next criterion is the voltage limit of the wires. If this parameter is exceeded, the line may fail due to breakdown of the insulation layer. Also worth paying attention to the materials used in the manufacture. They must be sufficiently plastic, resistant to active chemicals and high temperatures.

In the event that high-voltage wires ("Lanos", for example) are completely serviceable, it is necessary to search for the cause of the changes in the operation of the motor in other elements of the system. First of all, it is necessary to inspect the ignition coil and the spark plugs.

Current

Current leakage can occur for various reasons, the most frequent are the following:

• Damage to the outer layer;
• Malfunction of the ignition coil and cable caps;
• Contamination on the distribution cover and wiring.

All this contributes to the deterioration of the dielectric properties of the parts necessary for the operation of the car.

External factors

High voltage cables are constantly exposed to negative influences that reduce the period of use, including:

• Precipitation contributes to the formation of a variety of deposits on the ignition nodes. They increase the likelihood of leakage, having a conductive effect. Further, the voltage level decreases due to the damaged outer layer.
• Temperature regime. When exposed to high temperatures, the integrity of the spark plug caps is disrupted, which are placed next to the heated elements of the motor.
• Vibration effect. During the operation of the vehicle, vibration occurs, affecting the contacts of the lines.
• A low temperature leads to a decrease in the ductility of the wires, which increases the likelihood of damage to the caps and insulation.

What you need to pay attention to

Particular importance when buying has information that displays the brands of motors to which this product is suitable. On machines in which high-voltage pulses are generated with the minimum value of energy, cables with high distributed resistance should not be installed. If this rule is not observed, the spark power is reduced, and as a result, a partial ignition of the fuel occurs.

Using a tool such as a tester, you can easily determine the level of resistance of cables. An exception is a high voltage wire for a car, which has a special winding, due to the changeable values of the resistance in the engine.

The material used to make the insulation layer is selected depending on the required characteristics. The conformity of the voltage level of the car ignition system and the selected products is also taken into account. In the instruction manual for the operation and repair of any transport, the limiting value of the voltage is observed, which the cables must withstand without disturbing the integrity of the insulation. Optimum option will be a cable, complemented by caps and insulation from materials not subject to temperature influences (for example, silicone). In addition, it will reduce the likelihood of current leakage, due to the fact that it does not absorb liquid.

Change of engine operation

High voltage wires, together with the caps, must be systematically cleaned from moisture and dirt, after removing it from the motor. Regular cleaning also requires ignition coils, spark plug insulators and a distributor cap.

Damages on insulation can not only be seen, but also heard. In the dark hours after the hood cover is lifted, sparks that are accompanied by clicks will become noticeable. Often there is a glow next to the ignition system, the cause of this is a leakage of electricity and an increased level of humidity.

The work of the engine at high speeds begins to change in the case of inadequate wire in a non-metallic conductor. The sound changes and the motor starts to "touch". In this case, you can talk about the damage to the cable going to the candle. If the engine begins to stall, you must carefully inspect the center wire.

Varieties

The design of high - voltage wires includes caps, metal contacts, protective coating and conductor. Also used in the manufacture of combs, which are necessary for the collection of cables in bundles. Conditionally products are divided into several types, depending on the features of production and materials used.

High voltage cables with PVC coating and stranded copper sheath are classified in the first category. The second type are products whose protective coating is made of polyurethane. The most technological and modern option is considered to be cables with silicone insulation and conductor, for the production of which is applied Kevlar, polymer or glass fiber material. They prevent the occurrence of losses in the ignition system and maintain the required level of breakdown voltage, thus optimizing fuel consumption, increasing the power of the power unit and the spark. Also worth noting is the environmental friendliness and resistance to external influences. Products of each category are manufactured in accordance with technical standards and are selected depending on the required characteristics and budget.