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Volvo Truck Electrical Problems: 7 Common Faults & Fixes!

Volvo trucks are known to be one of the best truck manufacturers worldwide.

But even if they create the best trucks out there, these trucks sometimes face electrical problems on one of their journeys. 

Some of these fixes are easy to do, but there are also some complicated ones. 

Here are some of the common Volvo truck electrical problems and how to fix them. 

A Short summary of Volvo Truck Electrical Problems that are Common:

Typical Volvo truck electrical problems include battery-draining issues, Bluetooth non-connectivity, Engine Control Unit issues, electrical power supply issues, light control module issues, and headlight and turn signal problems. A digital multimeter can be used to diagnose faulty components.

Volvo Truck Battery Problems

Volvo truck battery problems include a dying battery, battery charging issues, and battery signals concern. 

A truck battery keeps getting these problems because of weather conditions, frequent electric drains, charging problems, corroded battery connections, and more.

There are some other Volvo truck battery issues, including charging problems. Also, in some cases, the battery may demand more power than the alternator needs. 

Easy fixes include repair or replacement of the corroded line in the battery and even a complete battery change. Some cases like the constant battery issues need battery replacement already. 

Volvo has offered a Warm Weather Protection Plan on Volvo truck batteries. If the issue in your Volvo truck is because of the snow or cold weather, they will cover your truck in this insurance. 

Volvo Truck Battery Draining Problem

There are a lot of factors why a Volvo truck battery keeps on draining. 

The list includes keeping truck accessories on, faulty electrical connections, faulty alternators, and dead batteries. 

Since some easy fixes exist, you don’t have to replace the batteries immediately. 

We know for a fact that batteries drain over time. But if it frequently drains and affects your daily business already, this is something you should address a fix immediately. 

If you notice that your Volvo truck battery is having an issue, assess how you use the battery’s power first. Maybe you are using too many accessories such as the truck phone charger, interior lights, headlights, and other truck accessories. 

You may try limiting your accessories to keep your battery up and running. Or, if you really can’t let go of any of those accessories, you may disconnect them right after use. 

This way, you can preserve the power in the battery, and it will not be wasted when idle. 

Now with electrical components, you must ensure they are in good condition. If one wire has issues, it will affect the battery entirely in the long run. 

That faulty wiring will cause your truck to demand more power from the battery because it can’t get enough due to the wire issue. 

Fix this immediately by sealing any electrical wiring or replacing any defective connections to avoid hurting your battery health. 

Check the alternator because it will drain the battery if it has a problem. If the battery is dead, replacing it with a new one is the only fix. 

Volvo Truck Battery Light Flashing

If the battery light keeps on flashing, it is telling you that there is something wrong. 

It would be great if you immediately found out why it keeps blinking. 

It can be caused by the battery wires and terminals, alternator and belts, over-usage of accessories, and even lost ground straps. 

Fixing whatever the cause is will stop the battery light warning from blinking. 

The moment you notice the battery light warning in your truck, no matter where you are, do not stop the car at a place with no help in reach. 

If the problem is the battery is dying, when you turn it off, the truck will need a pump of electricity to start it. The battery level might not be enough to start it. 

You can preserve the battery life by removing any accessories, turning off the air conditioning system, and turning off the radio too.

Volvo Truck Battery Connection

There will be times when the problem with a battery is its connection. 

The most common problem with the terminals is when it corrodes due to normal wear and tear or if the terminal connection is loose. 

You may check the terminals if they are tight enough and have no play. Check the cables and truck wiring to the battery to ensure that all are in proper condition with no burns and well insulated. You can replace the parts if there is a problem with any of them. 

You can buy a brand new terminal connection at any store. Make sure that it matches your truck and battery. 

Volvo Truck Battery Fuse

The fuse of a Volvo truck is located beneath the dashboard near the driver’s area. 

To check the fuses, remove the cover, showing you all the truck fuses. 

Usually, the problem with a truck fuse is when it is blown or burned. 

Also, it will be easy to notice defects due to burnt appearance. You can replace this easily using a clipper. 

Volvo Truck Bluetooth Problems

The typical Bluetooth problems in a Volvo truck include Bluetooth not pairing up with any phone or specific phone models, automatic unpairing when in use, and truck Bluetooth is undiscoverable by phones and vice versa. 

Also, you cannot select the Bluetooth option through the screen. The useful fix for all these problems is to remove all paired phones and start pairing again.

If it still doesn’t work, there are other ways to fix it. 

Another option to fix the problems mentioned above is using the isolator switch. Simply turn on and off the switch located behind your front offside wheel. Do this for around one minute. 

After this, start pairing your phone with the truck Bluetooth again. 

Now, if the isolator switch fix won’t do any good, you need to replace your radio unit. 

Volvo Truck Bluetooth is Not Working

To ensure that your Volvo truck Bluetooth will work, your phone should have sufficient power, ideally more than 50 percent battery life. 

This will ensure that if there is any interference for example a wi-fi connection, it doesn’t interfere with the Bluetooth connectivity.

Also, check if both the truck and phone are visible for pairing. You may also try restarting the phone and the truck. 

Volvo Truck Bluetooth Pairing

If the device and truck don’t pair, try using other devices to rule out if the problem is with your phone. 

This is vital to check whether the problem is in your phone or not. 

If it does not also connect with other phones, try switching off the isolator. It is like a restart for the truck’s Bluetooth. 

Volvo Truck ECU Problem

ECU or Electric Control Unit is the truck’s brain that controls the engine and other component features. 

Any problem with ECU will be a big headache for you. ECU is a computer with internal pre-programmed and programmable chips. Hence, it does not differ much from a home computer or laptop. 

If your ECU is having issues, you will notice some symptoms. It includes apparent loss of spark; the check engine light is on even after resetting; and intermittent starting problems. 

To fix this, check and replace the spark plugs, idle control valves, power supply, and ignition coils. 

Volvo Truck No Electrical Power

If your truck has no electrical power when you start the truck, and nothing is happening try to jump-start it first.

If this does not work, check if the battery is dead by using a multimeter. If the battery is found to be dead, it can be easily replaced.

Another issue that may cause your truck to not have electrical power would be a faulty ignition switch. If this is the case, it should be replaced. However, if the problem still persists, visit an auto electrician or mechanic at the nearest service center.

Volvo Truck Headlight Problems

Typical Volvo truck headlight problems are headlight low beam and headlights not turning off. We discuss them in greater detail below.

Volvo Truck Headlights Won’t Turn Off

When your truck’s headlight doesn’t turn off, you must disconnect it from the battery first. 

If you don’t do this, it will drain your battery dead. 

Remove the headlight fuse and headlight relay. 

The cause of this is problems with the headlight switch, daytime running light, module, light sensor, relay, or grounded wire. Replacing these parts would fix it. 

Volvo VNL Headlight Bulb Low Beam

If the Volvo truck has a low beam, there is something that you need to check and replace. 

One would be replacing the light bulbs, inspecting or replacing the fuses, or resetting the ECU. T

The moment you fIx these, everything will be fine with the headlight. 

Volvo Truck Light Control Module Problems

A Volvo truck Light Control Module or LCM controls all of the light systems of the truck. 

You will know that there is a problem with it when the headlight performance is intermittent, the tail lights are not working correctly, and all other truck lights do not seem to work as they are. 

To fix this, understand the faculty error codes given by the LCM; once you have deciphered the code, you will be able to know what to fix. 

Some fixes include resetting the program, checking other control units, and replacing the control unit. 

Volvo Truck Turns Signal Problems

The most common problem why turn signal malfunctions include flasher units, fuses, bulbs, wires, connectors, and switches. 

You can troubleshoot them with the help of a digital multimeter and light test. It will require you to test all possible sources to ensure you get the correct diagnosis. 

Typically, for flasher units, fuses, and bulbs, a resistance test can be done whilst for wires, connectors, and switches, a continuity test can be done to check if the components are damaged.

Any damaged parts can be replaced to get the turn signal working again.