Why is my blazer not starting?

If your Blazer won't start, the most common culprits are a dead battery, a faulty starter, fuel delivery problems, or ignition/immobilizer issues. Start with the basics and work toward more detailed diagnostics as needed.

First steps to diagnose a Blazer that won't start

Begin with quick, non-invasive checks that cover power, fuel, and security systems. The following steps are safe for most drivers to perform and can quickly identify the usual suspects.

• Check the battery: Do the interior lights and dash lights come on when you turn the key or press the start button? If not, the battery or connections are the likely problem.



• Listen for sounds when attempting to start: a single loud click often points to a weak battery or bad connection, while a rapid series of clicks can indicate a discharged battery or a faulty starter relay.


• Check the fuel level and listen for the fuel pump priming when you turn the key to ON (you may hear a brief hum from the rear of the vehicle).


• Look for the security/immobilizer indicator on the dash. If it stays on or flashes, the key may not be recognized by the system.


• Inspect fuses and relays related to starting and the fuel system. A blown fuse can prevent the engine from cranking or starting.


• If you have a keyless start, ensure the key fob is inside the vehicle and its battery is working; try placing the fob near the start button if needed.

If these checks don’t resolve the issue, more advanced testing may be required, which can involve diagnostic codes or specialized equipment.

Symptoms and likely causes

No crank, no lights when attempting to start

When turning the key or pressing start yields no engine movement and the dash stays dark, the problem is often electrical. The likely culprits include a dead or severely discharged battery, poor battery connections, a blown main fuse, or an ignition switch failure. A security/immobilizer fault can also prevent the engine from turning over.

• Test battery voltage with a multimeter (aim for about 12.6 volts when the car is off).


• Check for corroded or loose battery cables and clean/secure them as needed.


• Inspect the main fuses and the starter relay for signs of failure.


• Look for the immobilizer or key warning light and consider reprogramming or replacing the key fob if necessary.

Without power reaching the starter, the Blazer will not crank. If these checks don’t restore power, call roadside assistance for a safe assessment.

Cranks but won’t start

The engine turns over but fails to catch or run, which points to fuel or ignition issues, or a sensor fault. Common causes include insufficient fuel pressure, bad spark delivery, a faulty crankshaft position sensor, or a security-related interruption.

• Check for a valid fuel pressure at the rail using a gauge, if you have access to the tools and know-how.


• Inspect spark plugs and ignition coils for wear or damage; misfires can prevent starting even if the engine cranks.


• Scan for stored trouble codes with an OBD-II reader to identify misfires or sensor faults.


• Verify the immobilizer isn’t restricting startup; a related warning light or message may appear on the dash.

If you’re unable to confirm fuel or spark conditions safely, a mechanic can perform a more thorough diagnostic with diagnostic equipment.

Starts briefly then dies

A symptom that often signals a fuel delivery problem or a fuel-pressure fault, rather than an ignition issue. The engine may run momentarily on residual fuel and then stall if the pump isn’t delivering enough pressure or if the fuel filter is clogged.

• Check for a consistent fuel pump operation when turning the key; if the pump doesn’t prime, the pump, relay, or wiring may be at fault.


• Test the fuel pressure and replace a clogged fuel filter if necessary.


• Look for vacuum leaks or a faulty idle control system that could cause the engine to stall after start.

Persistent stalling after startup typically requires professional inspection to diagnose fuel delivery or sensor faults.

Starts and runs rough or stalls while driving

If the Blazer starts but runs poorly or stalls under load, the issue is likely fuel delivery, air intake, or sensor-related. Potential causes include dirty or failing fuel injectors, a clogged air filter, vacuum leaks, or a faulty idle air control valve.

• Check for abnormal idle speed and listen for misfires indicated by flashing check engine light.


• Inspect the air intake and filter for clogging or damage; replace if necessary.


• Use an OBD-II scanner to pull codes that may point to misfire, sensor, or fuel-system faults.

Ongoing rough operation warrants a professional diagnostic to avoid potential engine damage.

What to do next

Based on the symptoms you observe, these are practical next steps to recover the Blazer or arrange proper service.

• If the battery or connections seem suspect, attempt a jump start or have the battery tested and replaced if needed.


• For immobilizer or key issues, replace or refresh the key fob battery and ensure the fob is recognized by the vehicle; contact a dealership if re-synchronization is required.


• If a fuel issue is suspected, verify fuel level, listen for the fuel pump, and consider testing fuel pressure; avoid driving if you smell fuel or suspect a leak.


• Check fuses and relays related to starting and fuel systems; replace any blown fuses with the correct amperage.


• Use an OBD-II scanner to pull codes and interpret the results, which can guide you to possible faulty sensors or ignition components.


• If the vehicle is under warranty or you’re unsure about performing tests, contact roadside assistance or a qualified mechanic for a diagnostic visit.

Professional diagnostics can quickly identify issues that require specialized tools or expertise, such as fuel system diagnostics, ignition timing concerns, or immobilizer reprogramming.

Do-it-yourself vs professional help

Some checks are safe and effective to perform at home, while others require professional equipment and training. Consider the following guidance to decide your next steps.

• Do-it-yourself: basic battery tests (voltage, clean/secure terminals), fuse checks, fob battery replacement, listening for pump priming, and using an OBD-II scanner to read codes.


• Professional help: diagnosing intermittent starting issues, verifying fuel pressure and injector operation, electrical wiring faults, ignition switch reliability, starter motor function, and immobilizer/system reprogramming.

When in doubt or if you encounter safety concerns (fuel leaks, burning smells, or repeated failures), seek professional assistance promptly.

Summary

A no-start Blazer generally boils down to power, fuel, or security systems. Start with the basics—battery health and connections, fuses, and whether the immobilizer is recognizing the key—then move to fuel delivery and ignition checks. Use an OBD-II scanner to read codes, and don’t hesitate to call roadside assistance or a mechanic if the problem persists or if you’re unsure about performing any diagnostic steps.

What is the most common problem on a Chevy Blazer?

Common problems: Some of the most common problems with the 2022 Chevy Blazer include electrical system issues, brake problems, and structural errors.

Why is my Chevy turning over but not starting?

A Chevy that cranks but won't start is often caused by issues with the fuel system, the ignition system, or a sensor failure. Common culprits include a bad fuel pump, spark plugs, or crankshaft position sensor. To troubleshoot, check for fuel and spark, test sensors with a diagnostic tool, and inspect the battery and starter. 
This video shows a step-by-step process to diagnose a crank no start issue on a Chevy Silverado: 1mKIT'S Auto and Truck RepairYouTube · Oct 12, 2021
Fuel system issues

• Fuel Pump: A faulty or failing fuel pump is a very common cause, especially in certain model years. You may hear a strange noise from the fuel pump area, or the pressure might be low. 
• Injectors: Clogged fuel injectors can prevent the engine from getting enough fuel. 
• Fuel filter: A clogged fuel filter can restrict fuel flow to the engine. 
• Fuel level: While it may seem obvious, ensure you have enough fuel in the tank. 

Ignition system issues

• Spark plugs/Coils: Worn-out spark plugs or faulty ignition coils can prevent the spark from igniting the fuel. 
• Cap and rotor: On older models, a worn-out distributor cap and rotor are common causes for a no-start condition. 
• Starter: A bad starter can cause a clicking sound, and sometimes the engine may crank but not fully engage, or simply not start at all. 

Sensor failures

• Crankshaft position sensor: A malfunctioning crankshaft position sensor is a common culprit, as the engine's computer needs its signal to know when to fire the spark plugs and inject fuel. 
• Camshaft position sensor: Similar to the crankshaft sensor, a bad camshaft sensor can also cause a no-start condition. 

Other potential problems

• Battery: A weak battery may have enough power to crank the engine but not enough to start it. 
• Security system: A faulty anti-theft system can prevent the engine from starting. 
• Fuses and relays: A blown fuse or a faulty relay can cut power to essential components like the fuel pump or ignition system. 
• Timing chain/belt: If the timing chain or belt breaks or jumps a tooth, the engine's timing will be off, and it will not start. 

This video demonstrates how to inspect the fuse box for a potential crank no start issue: 59sGage Fixes EverythingYouTube · May 5, 2023
Troubleshooting steps

1. Listen and look: When you turn the key, listen for sounds like a clicking from the starter, a whine from the fuel pump, or a fast-spinning noise that could indicate a bad timing chain. 
2. Use starting fluid: Spray a small amount of starting fluid into the air intake. If the engine starts briefly, you have a fuel delivery problem. 
3. Check for codes: Use an onboard diagnostic (OBD) tool to read any error codes, which can provide clues about the problem. 
4. Inspect the battery: Check that the battery terminals are clean and tight and that the battery is fully charged. 
5. Test fuel pressure: Use a fuel pressure gauge to check the pressure at the fuel rail. A pressure test can help you determine if the fuel pump is working correctly. 
6. Check for spark: Use a spark tester to see if the ignition system is producing a spark. 
7. Check fuses and relays: Use a test light to verify that fuses are good and that relays are functioning correctly. 

What would cause a Chevy Blazer not to start?

The most common reasons a Chevrolet Blazer won't start are a dead battery, an alternator problem, or failed starter. Battery: A weak or failing battery can result in difficulty starting the engine and electrical system malfunctions.

What does it mean when my car has power but won't start?

A car with power but no start is likely caused by a faulty starter motor, a bad ignition switch, or a problem with the car's electrical connections. Other common culprits include a blown fuse or relay, a loose or corroded battery cable, a problem with the fuel pump, or a malfunctioning shift safety switch. 
Electrical and connection issues

• Faulty starter motor: If you hear a single click when you turn the key but the engine doesn't crank, a bad starter is a likely cause. 
• Bad ignition switch: This switch sends power to the starter. If it's faulty, accessories might work, but the engine won't crank. 
• Loose or corroded battery terminals: Even with a charged battery, corrosion or loose connections can prevent the flow of power needed to start the engine. 
• Blown fuse or faulty relay: A blown fuse or bad relay in the starter circuit can prevent power from reaching the starter. 
• Key fob battery (for push-button start): A dead or weak key fob battery can prevent a modern car from recognizing the key and starting. 

This video explains how to check for common causes like a faulty starter or a bad key fob battery: 55sFixITYouTube · Jan 23, 2025
Mechanical and safety issues

• Faulty neutral safety switch: In an automatic car, this switch prevents starting unless the gear selector is in Park or Neutral. Wiggling the shifter while trying to start can sometimes temporarily fix this. 
• Fuel system problems: If the engine cranks but won't "catch," a problem with the fuel pump or a clogged fuel filter could be the issue. 
• Security system lockout: The car's anti-theft system can malfunction and prevent it from starting. 
• Bad ignition coil or spark plugs: These are necessary for the engine to ignite. If they are faulty, the engine will crank but not start. 

This video demonstrates how to check the neutral safety switch and other potential issues: 59sHonest Mechanic ColoradoYouTube · Jan 24, 2024
Troubleshooting steps

• Check battery connections: Wiggle the battery terminals to ensure they are tight and clean off any white, powdery corrosion. 
• Try a jump-start: A jump-start can help determine if the battery has enough power to crank the engine, even if it shows a good voltage reading. 
• Check fuses and relays: Locate the fuse box and visually inspect the fuses for the starter and ignition. You can also swap a suspect relay with a known-good one, like the horn relay, to test it. 
• Check the gear selector: For automatic transmissions, try shifting to Neutral or jiggling the gear shifter while in Park to see if the safety switch is the culprit. 
• Replace the key fob battery: If you have a push-button start, try replacing the battery in your key fob.