What Would Cause All Warning Lights to Come On? Our Explanation

You are driving from work one day, and all of a sudden, all the dashboard lights come on. This can be scary and confusing. If the low fuel light comes on, the solution is easy because you will need to visit a gas station. But an all-colorful dashboard with all manner of warning lights is rare and can leave one confused and distressed.

Causes of all warning lights coming on

1) A malfunctioning alternator

Many people think that it is the car battery that powers the vehicle. In reality, it is the alternator that does all the work. The battery is responsible for starting the vehicle, but the alternator powers most of the vehicle's components when the engine is running. The dashboard is among the components that are powered by the alternator. A malfunction on the alternator's part while driving can make all warning lights come on.

The alternator turns mechanical energy into electrical energy, which is why it is a critical player in the proper operation of your vehicle. It has a rectifier that converts AC power into DC power and activates your vehicle's electrical systems. Though alternators last the entire life of the vehicle, they can malfunction, but when this happens, the dashboard can be a culprit.

An alternator can start malfunctioning due to the following;

• Overuse
• Exposure to water
• General wear and tear
• Overexposure to heat
• Frayed wires
• Faulty alternator parts

The solution

A bad alternator can mean any of its several components failing, the stator being the main component. If the stator is the culprit, you can rewind it. Rewinding a stator requires an expert. In the case where rewinding the stator is not possible, professionals advise replacing the entire alternator.

Replacing an alternator is simple, and you can do it at home. First, you will need to locate the alternator. Its location under the hood will determine how hard or easy it will be to replace it. You will require a voltmeter to test if the alternator is alright.

Replacing an alternator

The tools you will need are:

• Ratchet
• Extension
• Flat head screwdriver
• Wire brush
• Breaker-bar
• A belt tool
• Torque wrench
• Different size sockets

Here's what you need to do to replace the alternator:

• Start by disconnecting the negative terminal of your vehicle's battery. This is done to prevent any electrical shorts.
• Using the belt tool, remove the serpentine belt. Loosen the tension pulley and then slide the belt off the alternator pulley.
• Locate the electrical wires found at the back of the alternator. There are usually three connections. The bolts that hold the electrical wires onto the alternator terminals are removed using a socket wrench.
• Use a socket wrench to remove the mounting bolts, usually three. Remove the alternator.
• Brush the alternator's mounting base to ensure the current flow without interruption. The alternator's connection points to the bracket to ensure the alternator is securely grounded to the block. It would be best if you also brushed the bolts that secure the alternator to the bracket.
• Install the new alternator and follow the same steps as before but in reverse. The bolts might seize and fail to come out in the future or even corrode, making the car's electrical connection weak. To prevent this, apply some anti-seize lubricant on the bolts' threads before fastening them. Remember to torque the bolts. You can set the torque at 30 to 40 ft-lb.
• Using the belt tool, adjust the alternator pulley to slide back the belt. Tighten the belt to the previous tension and confirm that all the belts are sitting well on the pulleys.

2) A bad battery

If the car's battery has issues, it can cause all warning lights on the dash to come on. A dying battery can cause problems in the electrical systems and cause the lights to come on suddenly. Corroded or loose battery terminals are another reason the lights can come on. Poor connection of the terminals causes the voltage to fluctuate, making the electrical systems act up.

The solution

You should follow these simple steps to diagnose and cure a battery problem properly.

Check the terminals for any corrosion or if they are loose. If corrosion is the problem, use a wire brush and baking soda. Start by loosening the nuts that hold the terminals in place. Start by removing the black (negative) terminal, followed by the positive one. Once you have cleaned and reconnected the terminals, see if the problem is solved.

If the problem is not solved by cleaning the terminals, you may have to replace the battery. Unless the battery was drained accidentally by leaving the headlights or the ignition key in the ON position, the recommended solution to a dead battery is replacing it.

3) Damaged or loose wiring

There is a lot of wiring in your vehicle. A bad connection could mean a critical system or component will malfunction. But loose and disconnected wires happen all the time either due to normal wear and tear, age, attack by rodents, or after an accident. An electrical short can cause the car's warning system to fail to recognize which part is faulty, thereby making all the dashboard lights come on.

It is relatively easy to repair if the damaged wires can be seen or easily located. However, typical wiring issues are best handled by a professional car electrician.

4) A malfunctioning steering wheel positioning sensor

Your car has a sensor that communicates with the car's computer on how far the steering wheel has been turned. The computer uses this information achieved by the sensor to adjust the car's headlights. This information is also used for traction and stability control systems.

When the steering-wheel-positioning sensor malfunctions, there are several issues you can experience. The headlights might go off; sometimes, the dash warning lights will come on too. Diagnosing and correcting this problem requires the services of an expert.

5) An issue with the fuse box

The fuse box houses all manner of fuses to help keep the electrical systems in the car operational and safe. A fuse can have issues and affect others, or there might be a short circuit in one of the systems, which might cause some fuses to blow up. A problem in the fuse box can cause the dash lights to come on.

You can work on your car's fuse box if you know what to look for. A seemingly big issue can be solved in minutes and at a minimal cost. But you will need the following tools if you plan on exploring the fuse box;

• A multimeter or a test light
• Flashlight
• Screwdriver
• A new fuse or relay

There is a fuse diagram of what each fuse and relay is for. You can find the diagram inside the fuse box. You must use the correct fuse as a replacement. If you are still trying to figure out what to do, please take your car to a professional electrician to sort the problem out.

6) A malfunctioning engine control unit (ECU)

A problem with the ECU could lead to a number of problems, and the dashboard lights coming on is one of them. The problem could be a bad electrical connection between the ECU and the dashboard or the ECU itself.

The solution

Use an OBD II diagnostic scanner to know where the problem could be. You can visually check the condition of the ECU connection to see whether there is any corrosion. If it is suspected that it is the ECU itself with an issue, consider replacing it. A professional mechanic is the best person to do this job. But here are the basic steps one can follow to replace a faulty ECU;

• Start by disconnecting the negative battery terminal
• Unplug the connectors to the ECU. The ECU is usually located under the dash on the driver's side
• Unscrew the ECU bolts and install the new ECU in the reverse removal order.
• Start the car and test whether all lights are working as required.

Conclusion

All warning lights coming on in your car should not cause panic, especially after reading our explanation of what could be the cause. Knowing the possible causes of this problem should help you locate the source fast and correct the problem before it worsens or affects the rest of the car.