How to check high voltage wires on a car?

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

Most vehicles use high voltage wires to carry electrical current from the ignition coil or module to the spark plugs. Just like other parts of the car, they can fail during operation. Electrical and electromagnetic interference occurs as a result of a discrepancy between the quality of the automobile wire and the established parameters. They have a negative impact on electronic devices, without which it is difficult to imagine modern machines. The engine is also under attack due to the malfunction of the electronics.

What you need to know

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

• current flow should be from the coil only;
• offthe tip of the candle and up to the coil itself should be free of the slightest leakage;
• low resistance;
• resistance to sudden temperature fluctuations;
• resistance to environment and chemicals.

It is worth noting that the choice of cable must be made in accordance with the equipment of the machine. Equally important is the regular replacement of high voltage wires, especially those connected to electronic systems. The occurrence of voltage leakage is possible at the slightest malfunction, because of this, the degree of toxicity of exhaust gases increases and the quality of engine operation deteriorates.

Causes of failure

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

• no contact between high voltage cables and spark plugs;
• exceeding the set resistance level;
• poor quality insulation causing voltage leakage;
• break line under the insulating layer.

If the high voltage wires of the VAZ break, the voltage level decreases and an electromagnetic pulse occurs, preventing the transmission of the rated voltage to the candle. The resulting damage results in cylinder malfunction caused by delayed ignition, as well as engine malfunctions and critical vehicle sensors not responding correctly.

How to check high voltage wires forcar

In order to identify a damaged wire, you will need a regular multimeter, which is necessary for checking the ignition line. It is recommended to check when the sensors and the engine are unstable at idle. This device allows you to determine the level of resistance and identify a damaged line.

Cable resistance may vary, it is selected depending on the engine and manufacturer's recommendations. If the slightest discrepancy is detected, the line should be replaced.

Before you check the high voltage wires with a multimeter, you need to inspect them for chips, melted areas and other damage. Cable breakage is not uncommon, and often occurs as a result of touching engine parts that are heated to high temperatures or during inaccurate repairs. The contact with the surface of chemical aggressive substances also negatively affects.

Verification steps

On the contact part of the cables there should be no traces of the oxidation process and soot. Do not forget to check for gaps under the insulating layer. To identify weaknesses, you need to inspect the line with the engine running. If present, sparks will occur at disconnected points. For a more accurate check, it is recommended to turn off the lights in the garage or work in the evening.

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

The resistance diagnostic mode is selected on the device, the best option would be a range within 10 kOhm. The gap is determined by the absence of the slightest resistance in the cable. Such a product does not perform its tasks and must be replaced. The average cable resistance parameter is about 5-6 kOhm.

Voltage level

As noted earlier, the voltage directly depends on the ignition system used in the car and the make 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 is worth noting that the VAZ-2110 high voltage wires included in one set must have a similar nominal resistance, with a difference of no more than 2 kOhm. If this parameter is exceeded, it is recommended to replace the entire kit.

Features of choice

The fundamental factor in choosing is not only the manufacturer and brand of cables. The motor model requires no less attention. This is due to the fact that when replacing and repairing wiring, some features must be taken into account, depending 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 insulating layer. It is also worth paying attention to the materials used in the manufacture. They must differ sufficientlyplasticity, resistance to active chemicals and high temperatures.

In case the high voltage wires (“Lanos”, for example) turn out to be fully functional, it is necessary to look for the cause of changes in the operation of the motor in other elements of the system. First of all, it is worth inspecting the ignition coil and candles.

Current

Current leakage can occur for various reasons, the most common being the following:

• damage to outer layer;
• faulty ignition coil and cable caps;
• dirt on the junction cap and wiring.

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

External factors

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

• Precipitation contributes to the formation of a variety of deposits on ignition units. They increase the likelihood of leakage by providing a conductive effect. Later, the stress level decreases due to the damaged outer layer.
• Temperature regime. When exposed to high temperatures, the integrity of the spark plug caps, which are placed next to the heated engine elements, is violated.
• Vibration impact. During the operation of the car, vibration occurs that affects the contacts of the lines.
• Low temperature leads to a decrease in the plasticity of the wires, which increases the likelihood ofdamage to caps and insulation.

What to look out for

Of particular importance when buying is information that displays the brands of motors that this product fits. On machines that generate high voltage pulses at a minimum energy value, cables with a high distributed resistance cannot be installed. If this rule is not observed, the power of the spark decreases, and as a result, partial ignition of the fuel occurs.

With a tool such as a tester, you can easily determine the resistance level of cables. The exception is the high voltage wire for cars, which has a special twist, due to the changeable resistance values in the engine.

The material used to make the insulating layer is selected depending on the required characteristics. It also takes into account the correspondence between the voltage level of the ignition system of the car and the selected products. The operating and repair instructions for any transport indicate the voltage limit that the cables must withstand without violating the integrity of the insulation. The best option would be a cable supplemented with caps and insulation made of materials that are not subject to temperature effects (for example, silicone). In addition, it will reduce the possibility of current leakage due to the fact that it does not absorb liquid.

Change engine operation

High voltage wires together with caps must be systematically cleaned from moisture andcontaminants, having previously removed from the motor. Ignition coils, spark plug insulators and distributor cap also need regular cleaning.

Insulation damage can not only be seen but also heard. At night, after lifting the hood, sparks will become noticeable, which are accompanied by clicks. Often there is a glow near the devices of the ignition system, the reason for this is the leakage of electricity and increased levels of humidity.

The operation of the engine at high speeds begins to change if the wire in the non-metallic conductive core is unsuitable. The sound changes, and the motor starts to “troit”. In this case, we can talk about damage to the cable going to the candle. If the engine starts to stall, the center wire should be carefully inspected.

Varieties

The design of high-voltage type wires includes caps, metal contacts, a protective coating and a conductive core. Also, in the manufacture, combs are used, which are necessary for collecting cables into bundles. Conventionally, products are divided into several types, depending on the characteristics of production and the materials used.

PVC coated high voltage wires with stranded copper sheath are in the first category. The second type are products, the protective coating of which is made of polyurethane. The most technologically advanced and modern option are cables with silicone insulation and a conductive core, for the production of which Kevlar, polymer orfiberglass 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 sparks. It is also worth noting environmental friendliness and resistance to external influences. Products in each category are manufactured according to technical specifications and are selected depending on the required characteristics and budget.