1993 mercry capri not charging

What's the voltage at the battery with the car running ? Testing an not guessing is the way to do proper diagnostic's ! Battery light staying on , is there B+ voltage at the alternator connection's ? A new alternator won't make a bit of difference if no power to the alternator . Looking at a wiring diagram an testing the electrical circuit ,doing voltage drop testing , plus checking for DTC'S - diagnostic trouble code's . Some vehicle's charging systems are computer controlled . And looking at a wiring diagram i see your vehicles charging system is computer controlled . If you have done so already , take it to the dealer

nothing wrong with the ECM unless it has the voltage regulator as part of the system
indicates faulty wiring and faulty alternator
have a load test done on the battery
have an auto electrician do a full charging system check
charging voltage should be 14.5-14.8 volts DC
battery voltage should be 12-13.5 volts dropping to 11 volts when cranking the engine
make sure that the drive belt tension is correct and the belt is in good condition

It's best to relate symptoms to narrow things down. I assume you are still getting a dead battery when trying to start even after replacing the alternator and battery.
Get a volt meter. Harbor freight sells them ridiculously cheap (about $5). Measure the voltage at the battery terminals when the engine is running. If it is at least 13.5 volts to 15 volts then the alternator is charging correctly. If it is 12 volts then the alternator is not charging the battery.

If the alternator checks out ok, then check for things that could be draining the battery when the car is off. Usual suspect is the trunk light. Put your cell phone on video record into the trunk facing the light, then shut the trunk. If the light stays on, its because the switch in the latch mechanism is faulty. WD40 might make it work, or just pull the bulb. Also, check the glove box light the same way. Good luck...Chris

Whom ever did the parts replacement, didn't know
how to do any proper testing to resolve

Find a repair shop that can

if its not charging while running at14.5 volts or so you have a charging problem mabey no power to the alternator if its charging at 14.5 or so and the batery load tests good and its going dead over night you have a draw from some component in the system.

fit a new reconditioned alternator and not one from a junkyard

Hi:
The battery light means that your charging system isn't working, so you most likely have a bad alternator, or connection to the battery.
You can test your alternator with a volt meter.
First,get your battery 100% charged up. It should read about 12.6 volts.
Next, start your car, and check the voltage across the battery. It should be at least 14 volts. If not, you are not charging your battery.
Most auto parts stores will check out your battery or alternator for free, if you stop by and don't own or can borrow a volt meter.

Your alternator is charging however it is not still good if it does what you are stating. Also what is the condition of your battery if you have to keep jumping your car? Car batteries don't like to be completely discharge and may not hold there charge again once run dead and may need replaced... Alternator has to have be bad as it needs to be load tested to best determine it's true output. Most auto parts stores do a run test and no load test. Load test will tell amperage rate and true quality of an alternator.

its the alternator pulley thats defective and in order to pull the alternator you a have to take off the piece with the hoses on it above the alternator and you can wiggle it out

If your alternator is good then its your battery,its probally has a lowelectrolyte level,if you take the battery to an autozone they will put a load on your battery then a charge and let you know if its good right away and its free