regulator is bad inside alternator
Have the alternator tested.
If the battery is less than 2 years but doesn't seem to hold a charge
heater core is bad may need a coolant flush
The electric fuel pump is inside the gas tank
More than likely your alternator is on its way out.
Remove the belt from your 1993 Chevy G 20 alternator. Remove the alternator wiring harness. Remove the retaining bolts from the alternator. Reverse the process to install the new alternator.
Remove the wiring harness from the back of your 1993 VW Jetta alternator. Remove the three alternator retaining bolts. Remove the alternator belt. Reverse the process to install your new alternator.
It could be any number of things, from a faulty diode inside the alternator (the alternator could be working reasonably well but still have a bad diode) to a sticking relay. Sometimes those types of problems can be difficult to find, especially since they are often intermittent.
if a battery has a bad cell it wont hold a charge, but it could also be the alternator or the plug, i had a problem with the plug and had to change it from a junk yard, but before you do that i would check the easy parts first i.e the battery,then the cables, then the tension of the alternator belt, and finally the alternator itself along with the pigtail get a volt meter and test the current while the car is running, if it reads 13 to 14 volts the alternator is working and if it reads bellow 12 it is the alternator or plug. aojedamCheck your battery, it might be worn out and not able to hold a charge from the alternator.
how to change an alternator
The 1993 Chevrolet Cavalier voltage regulator should be mounted on top of the alternator. The alternator will be on the front of the engine.
You can remove your 1993 Mitsubishi alternator belt by loosening the tensioner pulley. Slide the tensioner pulley to the right. The alternator belt will become loose and can be removed. Reverse the process to put the new alternator belt on.