There’s a lot going on when you are driving a heavy duty truck. You need to make sure everything in your truck is running smoothly to avoid potential disasters. Heavy duty trucks are complicated and have a lot of moving parts, and for this reason there are many more dashboard symbols and gauges that truck drivers have to keep an eye on. Here is a guide to help you understand what your truck dashboard symbols, gauges, and warning lights mean.
Common Truck Gauges
Truck gauges provide drivers with vital information about the state of their truck and how it is functioning. All heavy duty truck dashboards have the following truck gauges.
Odometer: All vehicles have odometers, including heavy duty trucks, so most drivers are familiar with this dashboard gauge. The odometer shows the total mileage on your truck, and most odometers can also show the mileage of a specific route you have taken. This information is useful for knowing when your truck needs an oil change and other routine truck maintenance.
Voltmeter: This truck gauge shows the charge of your battering, either with numbers or with three colored sections. If your truck has a numerical voltmeter, it will read 14 to 14.5 volts when your battery is fully charged while your engine is running. This is the range your battery should typically stay in. If your voltmeter consistently reads below 14 volts or over 15 volts, then your batter is under charged or over charged, respectively, and you should have a diesel mechanic check your system. If your heavy duty truck has a colored voltmeter, you want the needle to hover in the middle green area. If it is in the red area to the left, then your battery is under charged, and if it is in the red to the right, then your battery is over charged. Keeping an eye on your voltmeter will alert you to charging issues before they turn into serious problems.
Tachometer: All vehicles have tachometers, too. The tachometer tells you the engine’s speed in revolutions per minute, or RPM. The diesel engines in heavy duty trucks are now designed to have maximum peak torque with lower RPMs.
Fuel Gauge: The fuel gauge is a vital auto and truck gauge in all vehicles. It lets you know how full your fuel tank is. Heavy duty truck drivers should check their fuel gauges regularly so that they can be sure they have enough diesel to make it to their destination. Running out of fuel while on the highway is a less than ideal situation that you want to avoid at all costs.
Engine Oil Pressure Gauge: The engine oil pressure gauge allows you to keep an eye on your heavy duty truck’s oil pressure. You want the oil pressure to stay between 30 and 70 pounds per square inch, or PSI. If your oil pressure is too low, your engine can suffer serious damage.
Air Pressure Gauge: This truck gauge monitors the PSI of each truck reservoir. You should regularly check both your primary and secondary air pressure gauges to make sure they do not fall below 90. If this happens, there could be a leak or some other problem with your air brake system. Pull over as soon as you can before your heavy duty truck experiences a breakdown.
Temperature Gauges: Heavy duty truck dashboards have a number of different temperature gauges. Some temperature gauges should be high while others should be low. Keep an eye on all your temperature gauges to keep your truck performing as it should be. The following are the different types of temperature gauges you will see on your truck dashboard.
- Coolant – This gauge monitors the temperature of the coolant and should be around 165 to 195 degrees Fahrenheit. If you notice that your coolant temperature is too high, you need to pull over when it is safe and let it cool down before continuing your drive.
- Engine Oil – This gauge shows the temperature of your heavy duty truck’s motor oil. If your oil is too hot, your engine can be damaged.
- Pyrometer – This gauge displays the temperature of your diesel engine’s exhaust. This can warn you that your heavy duty truck may have engine damage.
- Transmission – The temperature of your truck’s transmission is shown here. You can find out what a normal transmission temperature is in your manual. Normal temperature ranges vary by manufacturer.
- Rear and Forward Axles – The temperature of the oil in your axles is shown here. Forward-rear and rear-rear axle oil temperatures should stay around 160 to 220 degrees Fahrenheit for Meritor axles or between 80 and 200 degrees Fahrenheit for Dana Spicer axles. When your heavy duty truck is under heavy loads or climbing steep grades, it is normal for these axle oil temperatures to go up, as long as the temperature falls back to normal afterwards.
Dashboard Symbols and Warning Lights
Heavy duty truck dashboards have a variety of warning lights and dashboard symbols that can indicate both emergency and non-emergency issues. You should familiarize yourself with what the different dashboard symbols and lights mean so that you know if it requires immediate attention. The location, design, and color of each warning light and dashboard symbol can differ among truck manufacturers, but here are explanations of what the most common symbols mean.
Check Engine Light: The check engine light can be indicative of both major and minor engine issues. If your truck’s check engine light comes on, check to see if any other warning lights have come on as well, such as those showing that your diesel engine is overheating or that the oil pressure is low. Pull over when it is safe so that you can turn your engine off as soon as possible.
Alternator Check Light: If your alternator check light comes on, this could be informing you that your truck’s alternator is not correctly charging your battery. When this happens, you should pull your heavy duty truck over when it is safe and only use the necessary battery-operated accessories, such as your windshield wipers, headlights, etc., until you can get the alternator checked by a diesel mechanic.
Low Coolant Level Light: The low coolant level light tells you that your coolant levels are low. This does not need to be attended to immediately, but you should schedule truck maintenance in the near future so that a diesel mechanic can find and fix the cause of this issue.
Tire Inflation Light: This warning light lets you know that one of your tires is underinflated. A tire that is underinflated is likely to cause a serious breakdown or accident. When you see the tire inflation warning light up, find a safe place to park and manually check the pressure of each tire.
Schedule Heavy Duty Truck Maintenance with a Certified Diesel Mechanic
When one of your dashboard symbols or warning lights flashes to alert you of an issue, you should get the problem fixed as soon as possible to avoid further damage or breakdowns. Here at Certified Diesel Solutions, our ASE certified diesel mechanics can find the root of the problem and fix it quickly. We provide diesel engine repair and preventative truck maintenance services to keep you safe while on the road. Our diesel mechanics have years of experience and use all the latest tools and technology to accurately diagnose and repair any problem your heavy duty truck may have. To avoid experiencing a disastrous breakdown, schedule truck maintenance today. Give us a call at 865-964-6598 or reach out to us online.