Motor Expo 2026

"Why do the show lights not turn off after turning the ignition key?" This is what car users should study and learn. Various warning signs on the dashboard can be found in your car's manual to be able to maintain your car more effectively. 

•Showing, no (charging) light? 

The warning lights on the dashboard, or what some people call "show lights," have significant meaning and importance in car usage, because the term "warning light" is a symbolic message that communicates to the driver that one of the car's systems is having a problem or is starting to show signs of a problem. Many people, when they notice a warning light for any system illuminate, often panic and think it's a big deal because they haven't paid attention to the manual or learned how to use it correctly beforehand. And when they use the car, they don't know what systems in the car are malfunctioning. 

What you should not do is "absolutely do not place or attach anything on the dashboard." Many car owners place amulets, Buddha images, dolls, or even pictures of their significant others on the dashboard because they want confidence while driving. This is not a good thing at all, because it will obscure various warning signs that are crucial for driving, and damage can be mitigated when you learn about those warning signs. 

In newer cars with an ON-BOARD COMPUTER system, these matters must be given great importance because they are quite complex to use. A single screen can display multiple functions. Before getting to know the various symbols, let's look at the following stories. It's not a trivial matter; making a mistake will only lead to unnecessary loss of money and time. 

The first thing many people commonly do is place amulets or various spiritual items directly on the dashboard, which obstructs the upper part of the temperature gauge, perfectly covering the red line. And if they don't take good care of the car and don't even realize that the temperature needle has reached the red line, they only know that suddenly the car starts to feel sluggish and doesn't run well until the engine dies. Trying to start it again yields no success. Ultimately, it has to be towed to a garage, where it turns out the water in the cooling system is completely dry, and the cylinder head is warped. Repair costs amount to about 30,000 baht because the lower radiator hose burst at the clamp. If that fabric amulet hadn't blocked the temperature gauge, the repair cost might have been just a few hundred baht, as one water hose costs around 3-4 hundred baht, plus a small towing fee. 

Example 2 is a European car that showed a wrench symbol and a message advising to go to a service center, but the driver didn't know because they couldn't read English. Luckily, it wasn't too serious; the charging system just had slightly lower than normal voltage. 

Example 3: The battery warning light came on, but the car owner didn't know what it meant. They thought it meant the battery was full because they had only been using the used car for a few days. Eventually, the engine died, but it wasn't too serious; the alternator was just worn out. However, it wasted time and incurred unnecessary towing fees. 

Example 4: Suddenly, a triangular warning light with an exclamation mark inside started flashing and then turned off... Is it dangerous!? 

These examples show that car owners have no knowledge of engines and no one to advise or consult them. Therefore, it is good that we should get to know and learn. 

•Engine Temperature Gauge? 

This gauge is very important. When the engine temperature rises high, it signals that the engine is malfunctioning. The heat generated can cause unimaginable damage to the engine. In newer car models, temperature gauges are becoming less common, presumably following a trend to reduce clutter on the dashboard. Temperature display will use a thermometer symbol light instead. When the ignition is turned to the ON position, this symbol will light up in blue and then turn off when the engine starts or reaches operating temperature. When the temperature starts to rise above normal, reaching the level set by the sensor, the thermometer symbol light will illuminate again, but it will turn red to warn that the temperature is higher than normal. When the thermometer warning light illuminates while driving and is red, don't panic. You still have time to safely pull over to the side of the road. Some car owners panic excessively when the temperature rises high, pulling over as soon as they find a spot because they fear engine damage, without considering if it's safe or not. 

There are many reasons for high temperature, such as a leaking water hose, leaking radiator, cooling fan not working, etc. However, it won't cause much damage if you know and turn off the engine immediately before it reaches a critical stage. Most of the time, when the temperature stays high for a long time, the engine tends to die completely. Mild consequences include a warped cylinder head. Severe cases have even included a twisted and cracked cylinder block. When driving, it is necessary to constantly monitor the various gauges, making it a habit like looking in the side mirrors for safety.

•No power, no light, won't start? 

Speaking of this, it reminds me of a young person who thought the battery light meant the battery was full. Please don't laugh, because it's not strange to lack knowledge and expertise in a particular area. But once you realize you know and need to use a car, in this case, it's necessary to study further to ensure proper car usage and maintenance. The last moment we turn the key to start, all the warning lights will come on. After starting, all warning lights should turn off, except for things like the handbrake warning light or gear position. When the engine turns, the alternator works, producing electricity to send to the battery and power various systems whenever the engine is running. This warning light should not come on. But if this warning light illuminates or flashes while the engine is running, it indicates a problem with the charging system or power supply. 

While driving, if itlightsup, the first thing to do is find a safe place to pull over, or find the nearest garage or service center, but it should not exceed 5 minutes from when the warning light comes on. You should also turn off the air conditioning, radio, or any other electrical systems completely, because at that time, all electrical systems will draw power from the battery. If the battery is in good condition and fully charged, you might be able to drive longer. It's best to find a parking spot quickly, because the engine will soon die without electricity to power the system, eventually causing it to shut down.

There can be several causes. Minor ones include a loose or broken alternator belt. If the belt is broken or loose, the alternator won't be able to function. A blown fuse has also been encountered. More serious issues include a worn-out or expired alternator, such as worn carbon brushes, burnt coils, faulty diodes, or ultimately, a battery that doesn't hold a charge. Solutions depend on the symptoms. A very serious problem is a faulty alternator, with prices starting from 6-7 thousand baht for small to medium Japanese cars. 

•Driving along, engine oil is missing? 

Shaft melting or crankshaft bearing burnout, causing the engine to be unable to rotate, stems from problems with the engine oil not circulating in the system. There can be many causes, such as leaks, a punctured oil pan, or a faulty seal. In diesel vehicles, a leaking alternator rear seal or even a leaking oil filter rear seal has been encountered. These problems prevent engine oil from circulating in the system. When there is no circulation, the system pressure drops, and the engine oil can warning light will illuminate. 

Therefore, when this warning light illuminates, you should immediately pull over and turn off the engine, because it means that the engine oil is no longer circulating in the system. When this warning light comes on, don't panic. Check the water temperature gauge as well to see how high it has risen. If it's normal or only slightly high, you still have time to safely pull over to the side of the road. Once parked, you must check for oil leaks to determine where they occurred. If you can't find any, wait 5-10 minutes for the engine oil to flow back into the oil pan. If you check the engine oil and find that there is no oil, it means there is a leak somewhere. If no leaks are found, it might be due to a broken cylinder head gasket, causing engine oil to leak into the combustion chamber. In this case, the smoke from the exhaust pipe will be white like a 2-stroke motorcycle, or it might be leaking into the cooling system. You must wait for the engine to cool down, then open the radiator cap and check if engine oil has leaked into the coolant. If there is oil in the system, the water will turn a murky coffee color.

In this case, you must tow it to a garage or service center. Absolutely do not start the engine. If there is engine oil, you must continue to check why the engine oil is not circulating. There could be two reasons: a faulty oil pump or a faulty pressure sensor. In this case, you should not start the engine either. 

•Braking hard and the warning light comes on? 

The ABS symbol or brake warning light will illuminate when the ignition is turned to the ON position. Once the engine starts, this light will turn off. Sometimes, when braking hard, the ABS warning light may flash intermittently. Don't worry about this; it's because the ABS system is active. It will turn off by itself when you release the brake. However, if this warning light comes on steadily while you are driving normally, it indicates a system problem. It's best to consult your car's manual, which will tell you what caused it, as some brands have similar-looking warning lights, such as the handbrake warning light, worn brake pad warning light, or low brake fluid level. Consulting the manual will give you an initial diagnosis. If the brakes are still functioning, you can continue driving cautiously, but don't drive at high speeds for safety. Sometimes, it's due to mud or moisture on the sensor causing inaccurate readings. 

Another case that can be found is when turning sharply, a triangular warning light with an exclamation mark in the center flashes, or it might be a car symbol with a slippery road warning sign that flashes. This indicates that various stability control systems are actively working because the car is starting to lose stability. The stability control or stability maintenance system works to reduce the chance of losing control. When the car regains normal stability, the light will stop flashing. If this light flashes continuously, it means there is a system problem. You can drive normally, but when the car starts to lose stability, the system might not work. Therefore, you must drive with more caution than usual. 

•Engine light showing while driving? 

These various warning lights are designed to turn off once the engine starts. Suddenly, if the engine light comes on while driving, it indicates a problem with the engine system. If the car can still be driven and accelerated normally, you should also observe other gauges, especially the temperature. If the temperature is normal, you can continue driving, but you should not use high speeds or high engine RPMs. Some car models will switch to a limp mode to prevent damage, which will limit the engine's RPMs, usually to around 1,500-2,000 RPM. This is to prevent engine damage and to allow the car owner to safely drive the car back to a service center without needing a tow. This warning light is quite broad in terms of the problems it indicates. Sometimes, a broken wire or the ECU being unable to detect a signal will cause the engine light to illuminate, prompting inspection. In some systems, it doesn't cause immediate engine damage but rather long-term issues, so the system still allows the driver to continue driving. 

•Airbag? 

Another symbol to be aware of: if the airbag light or SRS symbol illuminates while driving, you must quickly take the car to a service center for inspection. Sometimes, it's due to installing audio systems, alarm systems, flashing lights, etc., where the wiring work might interfere with the system's signals. Most inspection intervals are around 50,000 or 100,000 km, for example. Sometimes, removing the steering wheel or related wiring can also cause the warning light to come on. It's recommended that if you need to remove the steering wheel, you should let a service center do it, because if there's a mistake, it could cause the airbag to deploy and lead to danger. Additionally, you must thoroughly study the user manual for the seatbelt system, especially if you regularly travel with children. 

•Out of fuel? 

I've experienced this often with unfamiliar cars. Due to complacency, not paying attention, the engine suddenly died even though the fuel light wasn't on yet. In most cars, when the fuel pump symbol light comes on, you can usually drive another 20-30 km. However, it's best not to let the fuel level drop below a quarter tank. At this level, you should refuel to prevent running out of fuel in an unsafe location. Many beginners don't know what it means when the fuel pump warning light illuminates, so they keep driving until they run out of fuel. If they're lucky, they'll run out near a gas station or someone will come to help. 

For premium cars, it's even more important to study extensively. Most of them have ON-BOARD COMPUTER systems that can display various functions and provide diverse readouts. You must thoroughly study the operating manual to understand what values it can show and what displays can be changed, as they are more complex than regular cars. It's best for car owners to study their car's manual. 

Source What do the warning lights on the dashboard help with? ? Warning signs are not…bad omens ! AUTOINFO Online