Usually when a 2006 Ford Taurus will not start, it is due to a component in the electrical system. The issue could be with the battery, ignition, starter or starter solenoid. Given so many different components, the best thing to do is to rule them out by process of elimination. Start with the easiest parts to replace and work your way down the list to the harder components to replace.
Clean the corrosion off the battery connectors using a mixture of baking soda and water. Mix three parts water and one part baking soda in a cup. Corrosion on the battery connectors can cause a poor connection between the battery and the electrical system. Make sure the connectors are tight. Attempt to start the Ford. If it does not start, move to the next step.
Connect a set of battery jumper cables to the battery on the Taurus and then connect the other end to a working car's battery. Attempt to start the Ford. If it starts, the problem is the battery. If it does not start, move to the next step.
Turn on the inside lights on your Taurus and attempt to start the car. If the lights dim, the ignition is sending power to your starter. This shows you that the ignition is not the issue. If the lights do not dim, replace the ignition.
Locate the two large post terminals on the back of the starter solenoid. Take a screwdriver and make a bridge between the two connectors. This connects the battery to the starter without turning on the starter solenoid. If you hear the starter turn on, the starter is not the issue. If the starter motor does not turn on, replace the starter motor. To avoid injury, wear safety goggles, as you will generate sparks when you do this step. Also, do not touch any metal on the screwdriver. This is an electrical connection and you could be shocked. In addition, place the car in neutral and set the parking brake for added safety.
Place the positive lead of a voltmeter onto the right terminal post and place the negative lead of the voltmeter against the starter casing. Have a second person attempt to start the Ford. If the voltmeter reads 12 volts, the solenoid is fine. If not, replace the solenoid.
