Simple Checks (Do these first!):
* Battery: This is the most frequent culprit. Check the battery terminals for corrosion (clean them with a wire brush if needed) and test the battery voltage with a multimeter. It should read around 12.6 volts when fully charged. If it's low, jump-start it or charge it.
* Battery Cables: Check the battery cables for corrosion and loose connections at both the battery and the starter. Tighten them securely if necessary.
* Ignition Switch: A faulty ignition switch can prevent power from reaching other components. This is harder to test without a multimeter and some knowledge of automotive electrical systems.
* Fuses and Relays: Check the fuses and relays related to the ignition system. Consult your owner's manual to locate the fuse box and identify the relevant fuses and relays. Visually inspect them for blown fuses (broken filaments) and replace any that are blown.
* Neutral Safety Switch (Automatic Transmission): If it's an automatic, this switch prevents starting unless the gear selector is in Park or Neutral. Make sure the shifter is definitely in Park or Neutral. A faulty switch can also prevent starting.
More Complex Issues (Require more troubleshooting or professional help):
* Starter Motor: The starter is what cranks the engine. A failing starter won't engage or may make clicking noises when the key is turned. Testing this often requires a multimeter and some knowledge of automotive electrical systems.
* Starter Solenoid: This is a part of the starter circuit and can fail, preventing the starter motor from engaging.
* Ignition Coil: This provides the high-voltage spark needed to ignite the fuel-air mixture in the cylinders. A faulty coil will prevent the engine from starting.
* Distributor (if equipped): Older vehicles like this Blazer may have a distributor. Problems within the distributor, such as a worn rotor or cap, can prevent proper spark delivery.
* Wiring Issues: Damaged or corroded wiring anywhere in the starting circuit can interrupt the power flow. This is often difficult to diagnose without specialized tools.
* Security System (if equipped): If the Blazer has an aftermarket or factory alarm system, it might be interfering with the starting process.
* Fuel Pump: While unlikely to entirely prevent *any* response, a faulty fuel pump could mean the engine won't crank or fire up once started. You'd likely hear little to nothing.
Troubleshooting Steps:
1. Start with the simple checks (battery, cables, fuses).
2. Listen carefully: Do you hear any clicking sounds when you turn the key? Clicking usually points towards the battery, starter, or solenoid.
3. Consult your owner's manual: It will provide information on fuse box locations and diagrams.
4. If you're not comfortable working on your car's electrical system, take it to a qualified mechanic. Attempting repairs without the proper knowledge and tools can be dangerous.
Remember safety first! Disconnect the negative battery cable before working on any electrical components. If you're unsure about anything, it's always best to seek professional help.
