follow the big red cable from the battery you will find it
starting problem can consist of duff battery, duff starter motor,duff alternator.
This is because the alternator has to put enough charge in the battery to charge it, the battery has to have enough amperes in it to turn the starter to turn engine over,the engine has to be running to drive the alternator, the alternator has to put etc etc
wirecutterman
June 2009