check the alternator first it just might be a bad battery (waste not want not)

 

That's a good point. But, don't you mean it could be a GOOD battery?
If the alternator is faulty the car will continue to run on battery power until the battery dies and then the whole car dies.
If the alt. is bad it won't recharge the battery. So, the battery could be good (just drained) and the alt. bad.

 

I know what you mean mate but if the alternator was bad it would fry the battery in no time and put all the lights on the dash on hence overload and 9 out of 10 it burns the dash out, so in cash terms you would check the voltage from the alternator engine running (14.4 ish but not higher than 15v) then you have a ball park to go at

 

or less than 12v forgot that