A Chevy Tahoe may fail to start for several reasons, the most common is a dead battery. However, lack of maintence can cause mechanical problems that will also prevent it from starting. A well-maintained car that won't start probably has a fault in the electrical system. Additionally, previous attempts to start the car could have flooded the engine.
Turn the key to the on position. If the dashboard lights do not come on, the engine doesn't make a chugging sound that indicates it is turning over, and the headlights do not illuminate, then the electrical system is at fault. The battery is the most common reason.
Pop open the hood to look at the battery, it should be located to the upper left. You are looking for foam on the top or sides of the battery. If the battery is foaming then it is leaking acid and a mechanic has to look at it. If the there is no foam then hit the electrical posts with a shoe or a rubber mallet. Doing this may reconnect the electrical posts if they have lost their connection.
Turn the keys to the on position, look for the dashboard lights to come on or flash briefly. If the engine chugs but still does not start then the battery is dead.The battery is removed by first unclamping the connections on the battery posts with a screwdriver. The retaining clamps can be undone by hand. Take the battery out by pulling on the built-in handle. Put in the new battery and redo the clamps and electrical connections. Do not over-tighten the clamps.
Turn the keys to the on position and check again for the lights to come on and for the engine to chug. If the lights come on and the engine chugs but still does not start, then the engine is flooded. A flooded engine means fuel is coating the spark plugs and preventing them from sparking. The Clear Flood mode is a procedure built into the car to dry the spark plugs.
Depress the accerator all the way to the floor. Next, turn the ignition on several times. The motor is now pumping air instead of gas and will dry off the spark plugs by blowing air over them. Take your foot off the accelerator after a few minutes and take the key out. Put the key back in and turn the car on. If the car does not start then there are mechanical or more complex electrical problems present and a mechanic is needed.
