No Start Diagnosis
Why doesn't your vehicle start?
There is a huge difference between cranking and not starting and no cranking and not starting. Cranking is the engine being turned by the starter and battery system. Cranking and not starting is more complicated.
First things first
1. Do the headlamps work?
The headlamps on most vehicles work independently from the ignition key circuit so if the headlamps work and work well, some voltage is available and you may have enough battery power, if they do not work check the battery and cable connections.
2. What works when you turn the ignition key to on?
If your dash warning lamps work and the radio works then we can assume this portion of the ignition circuit works.
3. What happens to the headlamps when you turn the ignition key to the start position?
Now make sure that the headlamps are turned on, then observe what the level of brightness is before the key is turned to crank and after. If they dim significantly and there is a noise (rerh, rerh, rerh) associated with it then we can assume your starter is cranking. If no noise is detected and there was no significant dimming, or only one click is heard you may have a faulty connection or faulty starter solenoid. If the headlights go out or If you hear a series of clicks or buzzing sound, you may have a weak, faulty battery or battery cable. In this case a jump start may do the trick.
Be careful connecting jumper cables in newer automobiles, follow the red to red and the black to engine ground. Never connect the black cable to the battery of the dead car, batteries can explode so connect to a nice metal part away from the battery of the dead car for the last connection!