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Speed drops when headlights are turned on: the principle of operation, causes and methods for solving the problem

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Speed drops when headlights are turned on: the principle of operation, causes and methods for solving the problem
Speed drops when headlights are turned on: the principle of operation, causes and methods for solving the problem

The long-awaited dream of an "iron horse" has finally come true, but how many difficult moments lie ahead for every road travel lover. Transport, like a living organism, gets sick, requires timely treatment and careful attention. Sometimes a problem arises - the speed drops when the headlights are turned on, and this is already a serious reason to think. What is the question?

Magic of prestige

Running lights undergo technical changes every day. Manufacturers vying with each other in a hurry to throw out new products to the international market, which become a highly aesthetic, practical item. Do you drive old optics? This is no longer prestigious, it betrays an economical owner. Everyone wants to match the modern era, fashion trends. The problems that arise are completely unsettling, and when the speed drops when the headlights are turned on, the mood inevitably falls. For a clear understanding of the situation, finding the essence of the issue, you need to get to the bottom of the reasons for its occurrence. Lights on the road are not just a toy. This is a significant component of high-quality movement, which plays an importantsecurity role.

Reason in brief

The result of the installation of heavy-duty lighting
The result of the installation of heavy-duty lighting

Experts identify several reasons for this behavior of optics. And the two main factors that explain why the engine speed drops when the headlights are turned on, auto mechanics call the following.

  • There are "ailments" in the generator part.
  • Their appearance was provoked by the introduction of new optical systems, not quite correctly matched to the parameters of the car.

Worth looking into more.

About high wattage lamps

Flipping through the pages of forums with FAQ, which discusses the reasons explaining why the speed drops when the headlights are turned on, one can come to the conclusion: it is not always justified to install bulbs with high power in autolights. This is especially true for vehicles that do not provide for such modernization. The desire of the motorist to install lights that are stronger in action is understandable, because the manufacturer does not manage to come up with high-quality lighting in all cases. As a result, the road is poorly lit, you have to strain your eyes, especially in bad weather, in rain or fog. "Innovation" with flashlights leads to even more problematic situations.

Overheating as the cause

RPM drop when headlights on
RPM drop when headlights on

One of the reasons why the speed drops when the headlights are turned on is overheating. All the work of "cool" lamps is reduced to the development of excess heat, resulting in the melting of the reflector. This applies not only to incandescent lamps, but also to halogens, LEDs. Solid sealing of the case does not allow heat to escape. Where can he go, how not to start melting the elements in the structure? It comes down to the deformation of the plastic itself.

The result of installing heavy-duty lighting

For each car, engineers select lighting devices - this is the work of more than one day or even a month. The light is selected from a variety of options, tested, set to specific parameters of the "steel dude". Independent experiments of drivers lead to blinding the eyes of oncoming motorists, provoking an emergency situation on the route. In constructive terms, this does not lead to anything good: the engine speed drops when the headlights are turned on, you have to look for a way out of an unexpected problem situation.

Casuses with a generator

Why does the engine RPM drop when the headlights are on?
Why does the engine RPM drop when the headlights are on?

Difficulty with the alternator is a possible factor in the RPM drop when the headlights are turned on. Troubleshooting is as follows:

  1. The power unit is running and the low battery indicator is on steadily.
  2. Boiling off, completely discharging the battery.
  3. The lights give a weak beam.
  4. The horn has almost no signs of life.
  5. There was an incomprehensible noise in the generator unit.
  6. Battery low.

Getting out of problems with the generator

Correct diagnostics is a sure way to understand why, when the headlights are turned on, the speed drops in the Ford EFI or another foreign car, to eliminate the problem of the mechanism. The easiest step tocorrecting the situation - checking the fuse. If it is in good condition, you will have to inspect the unit itself for uninterrupted rotation of the rotor, the integrity of the belt, electrical wires or housing. No defects? It's time to look at the brushes, contact rings. There is a high probability of wear or deformation.

Slip rings get clogged with graphite dust. Do you hear a whistle when the device is operating? It's time to change the bearings with a preliminary inspection of the seat. On models from previous years of production, turning the slip rings can help. Rotor windings are replaced when worn. What else leads to a turnover drawdown?

Electrical Faults

What causes the RPM to drop when the headlights are turned on?
What causes the RPM to drop when the headlights are turned on?

Current leakage can be the reason why the speed floats when the headlights are turned on. Here you can not do without a qualified diagnostic technique. A drawdown can occur during the installation of an emergency alarm, radio, cameras, navigators, and other equipment. In 90% of cases, difficulties are caused precisely by the independent modernization of the vehicle. The worst thing in this regard is the deep discharge of the battery. With independent intervention, the battery may one day simply stop working, then the engine will completely refuse to perform tasks. Up to 75 mA, the current leakage rate is considered normal. How to identify such a nuisance before checking into a professional service?

  • Purchase a simple multimeter. It will cost 300 rubles, and the benefits will be tangible.
  • The hood opens, the negativebattery terminal. It needs to be removed.
  • The tester is put into the electric current measurement mode. Measurements are taken with the probes of the device. To do this, they must be placed between the terminal and the battery contact.

Reasonable to ask professionals - what to do?

Solving battery problems

Boiling, complete discharge of the battery
Boiling, complete discharge of the battery

“I turn on the headlights - the speed drops. What is happening and how to fix it? - these are the questions that often torment motorists. You can highlight the common difficulties with the battery and how to resolve it.

  • The case cracks, unable to withstand the loads, you have to change it.
  • The battery is low, needs to be recharged and spend 4 to 12 hours on it.

When the car is in the cold for a long time, it should be periodically warmed up, even without the need to move. Some owners of vehicles choose the wrong battery, making mistakes with the dimensions, stubbornly squeezing the device into the niche of the engine compartment. Mounted incorrectly, reversed polarity.

The way out of all that has been said is to check the system as part of maintenance, consult with the masters. Their experience and knowledge help out. On average, the battery life is calculated by the developers for five years. What else do they recommend?

Effective algorithm of actions

fuel level violation
fuel level violation

Among the frequent motives, experts note a violation of the fuel level. The result is a drop in the dynamics of the car. Prolonged work on scarce, low-quality fuel leads to the failure of its operation. Air entering the carburetor, malfunctionson-board computer, obsolescence of spark plugs - all these factors are among the obvious causes of a malfunction in the functioning of the motor. Poor-quality fuel can serve as a determining factor explaining why the speed drops when the headlights are on. In this case, a step-by-step algorithm is recommended:

  • It is necessary to adjust the fuel level and XX. Manipulations are carried out on a warm motor. The "quantity" screw must be turned clockwise, increasing the number of revolutions.
  • Replacing candles helps. Products may be of poor quality. Malfunctions in candles can be recognized not only by the operation of the lamps. The motor twitches, the fuel expense item exceeds the expected figures. The composition of the exhaust gases is replenished with carbon dioxide. The engine does not want to pick up speed. The consequence will be detonation in the cylinders, as a result of which the power apparatus is completely deprived of power characteristics. The car drives unevenly, stalls halfway. After 20 thousand km, it is better to change the candles to new ones. Classic options can be replaced after 15,000 km. Platinum ones change less often - after 100 thousand kilometers, however, they are not cheap. Finding the "wrong" candle is easy with the naked eye.

Fuel control

Overheating is one of the reasons for the drop in speed
Overheating is one of the reasons for the drop in speed

Close attention to the level of fuel resource, to its quality allows you to avoid costly engine repairs. Undiluted, pure, from a trusted supplier, it can extend the life of all mechanical components.

Checking filters

slip rings
slip rings

You should definitely do this, because the motor power is reduced for this reason. The result is increased energy consumption, a waste of finances. Saves to some extent cleaning the air filter. The priority is replacement. Flushing the idle speed sensor will have a positive effect. It falls out of operation due to the ingress of contaminated oil into it. Cleaning will have the desired effect when using a carburetor flush or exposure to aerosol liquids. The sensor needs to be pulled out, washed. The needle is cleaned with an aerosol. In this important matter, increased accuracy is required: it must not be allowed to fall under the spring, there is a risk of failure of the device. Strong wear of the power unit itself can lead to a drop in speed.

The question of why the speed drops when the headlights are turned on is easy to figure out. It is enough to apply a competent integrated approach, contact a car service on time, with the first signs of problems.

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