How to Tell If Your 4x4 Switch Is Bad? And Ways to Fix It

The 4WD in a car is a feature that adds power to your wheels and enables trouble-free driving in all road conditions, including where traction is completely low. The beauty of this is that your car can take you anywhere smoothly. From regular driving on smooth roads to rough terrain, mud, snow, or extreme conditions, the 4WD system takes you beyond the driving limits of the two-wheel drive car.

However, like many other car parts, the 4WD functionality may fail. From time to time, a driver may encounter unwelcome situations where the four-wheel drive mode becomes problematic, compromising the vehicle's performance. This malfunction may arise from a faulty 4x4 switch.

But how can a driver tell that his 4x4 switch is bad? And if indeed it is bad, how can it be fixed?

How The 4WD System Works

To diagnose any fault in the four-wheel drive functionality, it is crucial first to understand how it works. A four-wheel drive is a drive-train system that provides power directly to the four wheels in your car. Normally, a vehicle is either a front-wheel or a rear-wheel drive.

The 4x4 system has two or more axles, and when engaged, the rear and front drive shafts are locked together and work in unison to turn all four wheels. This provides more wheel grip and traction on the surface, ensuring faster acceleration and the ability to overcome any road condition that inhibits forward movement.

While some modern vehicles engage their four-wheel functionality automatically depending on road conditions, most vehicles require the driver to manually turn on the 4WD Mode by pressing a button or turning a four-wheel lever lock. Some vehicles require the driver to halt completely before turning on the lock. The manual 4x4 turning on and off is designed to control fuel consumption since the Mode makes the vehicle gasoline-thirsty! 

Although the 4x4 systems differ in car brands, the basics are the same. When you engage the four-wheel drive mode, the 4WD actuator locks the shift forks and gears in the differentials. This enables the two axles to rotate uniformly as one unit, turning all four wheels in unison.

The power is distributed equally on all the tires, a function that drastically improves road traction. In modern cars, electronic solenoid switches activate the actuator in the differentials, while old models used vacuum hoses with pressurized air to activate and lock the differentials into four-wheel Mode.

How to Tell Your switch is Faulty

How would the driver know that the 4x4 switch is not working? The 4WD transfer switching system enables the car to move efficiently through various road conditions. However, the selector switch may fail to work when you engage it.

There are several ways the driver can ascertain that the 4x4 switch is not working properly. These procedures include the 4x4 dashboard light, gear shifting issues, difficulties remaining in the 4WD Mode, or the 4WD Mode failing to disengage.

1) Blinking Dashboard Light

A light will indicate the 4x4 Mode on the dashboard. However, when the transfer switch is faulty, the indicator light will flash or blinker continuously. This tells you that the car system has not properly shifted from normal to four wheels. Alternatively, it may indicate other underlying problems with your 4x4 transfer system. This is the easiest way to tell that your 4x4 switch is not functioning; from the comfort of your cabin. To the 4x4 enthusiast, this is an unwelcome distraction.

2) Difficulty Staying in 4WD Mode

If you find that your car keeps on disengaging from the 4WD Mode without your input, this is an indicator that the 4x4 switch is faulty. 

3) 4x4 Mode Failing to Engage

You may find that every time you engage the 4x4 Mode, the system fails to engage, or at times if it does engage, it gets stuck, and you are unable to disengage from the Mode even when you switch off the 4x4 system. Though there could be many reasons for this failure, it still points to the possibility of the 44 switches being faulty.

4) Faulty Gear Shifting 

Another common symptom of a faulty 4x4 switch is difficulty shifting between gears. Normally, a 4WD gear system range between high and low four-wheel drive gears. This could indicate that the actuator or the transfer box is faulty and thus cannot effectively switch between two and four-wheel modes.

Alternatively, check whether your 4x4 switch is working properly by raising your car off the ground and engaging the four-wheel drive mode. Afterward, step on the accelerator and get someone to check whether all four tires are rotating together in unison. If you discover that only the front (or the back) wheels are receiving power from the engine, the 4x4 switch is not working.

There could be other pointers to a probable damaged 4x4 switch. These range from unusual fluid leaks in the transfer boxes to growling and grinding noises as your car cruises. All these symptoms require immediate attention to rectify the underlying issue and maintain optimal car performance. 

How to Fix a Bad 4x4 Switch

Being conscious of various functionality issues in your four-wheel drive car will put you in a position to deal with the problems when they occur. The first line of defense is to try and diagnose the problem to determine whether it is a minor issue that you can fix or requires expert fixing.

The most common problems associated with the 4x4 system are either the 4WD drive failing to engage upon switching on or the car getting stuck in this Mode when you disengage. Moreover, the 4WD may keep disengaging from its quite often. These malfunctions reduce the vehicle's capabilities by inhibiting its power or misusing it when not needed. 

A faulty 4x4 switch indicates that the 4WD functionality is not properly engaged, and you could have a technical problem. The problem could be related to one or more of the following:

• A faulty electrical circuit within the 4WD components
• A damaged/leaking vacuum hose in the transfer console
• Actuator/transfer console failure
• Faulty solenoid or relay switch, especially in modern 4WD cars
• A seized differential/axle due to poor lubrication.

The key rule of thumb for all 4WD drivers is to regularly shift into the 4WD Mode even when not needing 4WD performance. This ensures the system keeps well lubricated and set for when it will be required.

It would be best if you began rectifying the problem by performing basic troubleshooting exercises, which could lead you to decide whether to call the mechanic. You could perform a DIY before deciding to call in the mechanic.

Rusty Points

Begin by checking the small things such as switches, wiring, connections, and fuses that may be faulty and thus prevent electric currents from reaching critical components of the 4WD switching system. Check for corroded or broken electric wires and contact points. Use a corrosion remover such as silicone spray lubricant on the parts and then test your 4WD system again. Alternatively, turn the engine on and off when you see the 4x4 light flashing.

Rusty and corroded parts may prompt the system to record error messages that are then communicated to the driver through the flashing light and a failed 4WD engage/disengage system.

Check Your Tire Pressure

Sometimes, unequal tire size and pressure can trigger a malfunction within the differentials causing the 4WD to fail. This could lead to the system sending failure messages or failing to engage/disengage the 4WD Mode. Check your tire sizes and inflation to ensure they are uniform, and then test your 4x4 system again. 

If the flashing light results from the 4WD gear failing to disengage, turn off the engine and turn it on. Still, you could reverse your car for a short distance before driving forwards again and then disengage the 4WD Mode. If it is still stuck, drive your car in Low gear for some distance and then disengage the 4WD Mode.

Leakages within the actuator/transfer console lead to the inability of your car to shift gears properly from 2wd to 4WD. Such leaks can only be fixed by an expert who can effectively deal with them to restore your car's normal 4x4 functionality. 

If troubleshooting and the DIY exercises fail to resolve your 4x4 switching problem, you need to call in an automotive expert to fix the problem effectively. It is critical to always seek a professional diagnosis of your 4WD transmission system every time you feel there is a problem beyond your scope. Such a check would go a long way to unearth any mechanical or electrical issue that might be affecting the overall performance of your 4x4 drive-train. 

But it is paramount always to keep your 4x4 system in constant check to ensure its function. A long period of disuse may cause the system to become clogged, packed up, or lack lubrication, making it dysfunctional when you need it most.