No motorists ever want to turn key and nothing happens, but lights work. This can be quite unnerving and frustrating. What will you do if you find yourself in this situation? Do not panic; this is a common problem that requires a simple fix.
A faulty starter relay or solenoid is the most common cause. And a dead battery can also cause it even though the headlight is lighting and the radio is playing. If the latter is the root cause, the light will not shine brightly as it should. Other possible causes can cause the underlying issue.
This article will discuss the meaning and the various reasons why nothing happens when you turn the ignition. It’ll also tell you what to do when a car won’t start; no light, no sound, and what to do when nothing happens but the light and radio work.
What could cause you to turn the key on and nothing happens but the lights work?
Before answering questions like, why won’t my car start, but I have power, let’s precisely check how a car starts when you turn the ignition key. This will give you a full understanding of what we’ll discuss below.
When you insert your car key into the ignition and turn it to the ON position, the system sends an electric signal to the car computer. As you turn the key a little further, an electromagnetic force pushes the starter solenoid, which pushes the starter motor gear pinion and allows it to intersect with the flywheel.
The solenoid opens a circuit across its electrical terminals to communicate with the starter motor. As a result, the motor pinion rotates, torquing the flywheel, which drives the crankshaft to spin and start the vehicle.
In newer cars with a push start button, the starter motor starts the vehicle when you depress the brake pedal and the push start button.
This shows the car engine has the necessary power to start. The pinion gear returns when you release the car key, letting the engine run independently. Now let’s see why you turn the key nothing happens, but the battery is fine.
There are three scenarios here. They are as follows:
- Nothing happens at all
- You heard a single click
- The car is turning over but not starting.
We’ll examine the probable causes one by one, starting with the first scenario.
If nothing happens at all
When you turn the key and nothing happens at all, it means the starter motor is not receiving power. This means you have issues with the ignition system. The issues are likely from the starter solenoid, battery, ignition switch, or lousy immobilizer.
Faulty starter solenoid
The battery sends power to the starter solenoid when you crank the engine. The electric flow passes through the coil to push the pinion gears to intersect with the flywheel. If the starter solenoid is faulty, it’ll not transmit the electric flow to the starter motor, and there’ll be no sound when you crank the engine.
In this case, the horn, radio, headlights, and all other lights will work as they should since the battery is charged.
Bad or poor electrical connection
Another probable cause to consider when asking what is wrong when you turn the key and nothing happens is poor, loose, or corroded electrical harness.
The radio, horn, and lights must have good electrical connections. And if the lights, horn, and radio are working properly, you have a charged battery.
In such cases, you have poor, corroded, or loose electrical connections from the battery to the starter motor, but the connections to the lights and radio are working as they should.
Faulty ignition fuse or switch
Once you turn on the ignition key, it closes the electric circuit that travels from the battery to the starter motor. If the switch is broken, it’ll prevent the battery from transmitting power to the starter motor even when fully charged.
In the same circumstance, if the ignition fuse cuts, it also prevents electric flow from passing to the starter. You’ll need to replace the blown fuse with the same amperage to rectify the underlying issues. However, remember that something caused the overload on the electric current. So, you need to track and fix the root cause before changing the fuse.
The immobilizer is a broad and interesting topic. We published interesting articles on Toyota immobilizers and Honda immobilizers. Read these articles to clearly understand how immobilizer works and what is it.
Without immobilizers, car thefts will easily steal your car. It is a system that recognizes a radio signal from your key transponder before sending electric flow to the starter. If it doesn’t recognize your keyfob, the engine will not start. Unfortunately, the immobilizer can fail and prevent electric flow from passing to the starter motor.
Although car manufacturers produce immobilizers in different ways. In some vehicles, a faulty immobilizer will crank the engine, but it won’t start, while it won’t allow the car to make any sound in other vehicles.
If you hear a click
If you turn key lights on, no start, but you hear a click; the electric flow is getting to the starter solenoid. In this case, the starter solenoid is activating but not strong enough to drive the starter motor to drive the flywheel and start the engine. Let’s look at the probable causes below.
You have a low battery if you hear clicks or weak cranks when you turn the ignition, but the car doesn’t start, and the radio and lights are functioning. The low battery still has some power to play the radio and turn on the lights but can’t power the starter motor – the starter motor draws more power than the radio and lights.
If the battery is too low, the lights will be dim, and the radio or any media system will disturb at higher volumes.
Corroded or loose battery terminal
Another prevalent cause is loose or corroded battery terminals. The necessary electrical systems will not receive the required electric flow if the terminals are corroded or loose. This will make you think the battery is low or corroded.
Lousy starter motor
If the starter motor is damaged, it can’t do anything with the electric current it receives. The starter motor can either make a single click per crank or repeatedly revolve without starting. It can be difficult to determine if the starter motor or the solenoid is the root cause.
Let’s be clear here; engines don’t seize overnight, and they’ll give you a rattling, clicking, or knocking noise before they seize. Several issues like empty engine oil or faulty internal components can cause seized engine. However, this should be the last thing to consider.
If you suspect a seized engine, take a sizable spanner and turn the engine. The engine is okay if it turns 360 degrees without stopping. But if it stops at a certain point or does not turn, you have a seized engine that needs overhauling or replacement.
If the car is turning fine but doesn’t start
There is an endless list of things to look into if the car engine is revolving fine but not starting. If the root cause is not the battery, other potential causes are;
- The malfunctioning powertrain control module
- Faulty crankshaft sensor
- Timing belt/chain
- Compromised fuel delivery
- Loss of engine compression
- Lousy crankshaft sensor
- Broken camshaft.
What to do if you turn key and nothing happens, but lights work
To fix the underlying problem, you need to know the signs. If there’s no sign, but the lights, radio, and horns are working fine, check the starter solenoid, the immobilizer, electrical connections, and the ignition switch.
If the starter solenoid is burnt, frayed, or damaged, replace it with a new one. If that is not the root cause, check the immobilizer and ensure you’re starting the car with the right key. The immobilizer may not allow the car to start if you use a spare key without a transponder. Check if the car has starting security and enable it.
Now, narrow it down to electrical connections and the ignition switch. Start by checking the battery connections and cleaning any corrosion on the terminals. Also, tighten the battery connections if they are loose. If none of these could rectify the underlying issues, have a mechanic diagnose the root cause. It could be that you have a faulty ignition switch.
If you hear a click, then nothing happens.
Check the battery connections and ensure they are properly tightened and free of corrosion. Also, check the battery and ensure it is properly charged. To test the battery, get a Multimeter and connect the probes to the positive and negative battery terminals. You should have around 12.6 volts. Anything below this shows the battery is low.
If a single or multiple clicks come from the starter motor, but nothing happens, have your friend tap the starter motor with your wheel spanner or any metal object while you start the vehicle.
If this fixes the problem, you have a failing starter motor that needs repair or replacement. Drive to your local mechanic to inspect the motor and see if you need a new starter motor or if it needs repair. However, you can get a new motor and replace it at home. It is a simple fix that anyone with a basic understanding can do.
If the problem persists, get a sizeable spanner and turn the engine. You have a serious issue if the engine is hooking somewhere or not turning. The best solution will be to tow the vehicle to a mechanic garage and have the mechanic inspect and rectify the leading cause.
The mechanic will disassemble the engine and examine internal components like the valves, pushrods, camshafts, rocker arms, crankshaft, bearings, pistons, and connecting rods.
If the engine is revolving fine but not starting
If the engine is cranking fine but not starting, you have to start by checking if the ignition coils are getting electric juice and if the fuel pump is supplying fuel.
If there’s no fuel, you likely have a bad fuel pump. All you need to do is replace the pump. Check the fuel pressure regulator and inner and outside fuel filters if there’s a low-pressure fuel supply. Replace clogged filter or defective fuel pressure regulator.
What if there’s no light on the ignition system? The probable causes can emanate from a burnt ignition fuse, loose or disconnected earth wires, or a lousy crankshaft sensor.
Other possible causes could be a broken camshaft, loose engine timing, engine seizing at a certain point, loss of engine compression, and malfunctioning powertrain control module.
Frequently Asked Questions – FAQs
Q: Why won’t my car turn over, but the lights come on?
If the headlights and other electrical appliances on your car are working fine, but the car is not coming on, the cause is likely ignition or the starter motor issues. In this case, the battery is working fine. However, other things can be the cause, depending on how or whether the engine revolves.
For instance, if you hear nothing and the lights are shining bright, you likely have an immobilizer, ignition fuse, or ignition switch issue. But if you hear a click and the car is not coming up, you likely have loose battery connections, a lousy starter motor, or seized engine. If the engine revolves fine but not starting, you have ignition issues, fuel delivery issues, bad crankshaft sensors, and loose, broken engine timing.
Q: Why is my battery dead, but the lights still work?
The headlights, radio, and other car accessories use much less power than the starter motor. Therefore, your car battery may be undercharged and still carry the lights, radio, and other electronics but cannot provide the required power needed to run the starter motor. In such scenarios, the starter motor will spin very weakly but unable to move the flywheel.
We have seen what is wrong when you turn key in ignition and nothing happens and the possible causes of no sound when turning key in the ignition. At this point, you know what to do when you turn key, and nothing happens, but lights work. Whether there’s a click, the engine revolves fine, or there’s nothing at all, you can easily point out the probable causes.
Follow the above guidelines religiously to track and rectify the leading cause. However, if you don’t like getting your hands dirty under the hood, contact a mechanic to diagnose and proffer a solution to the underlying cause.