I have changed the alternator on my 1990 Buick Park Avenue and it still has to be jump started. Why?

I didn't change the battery though, could this cause the problem? It runs fine and then just kills! Please help me, I am a single Mom.
I have changed the alternator on my 1990 Buick Park Avenue and it still has to be jump started. Why?
The primary electrical system is such a pain in the butt!



I am hopeful I'm not insulting you here, but so you understand what's going on, a brief explanation first.



When you start the car, you are activating the battery to provide electricity to the starter motor. Once the car starts, the current is shut off to the starter and the alternator starts charging the battery again. There are other things going on also, but that's the basics for starting the car.



Since the car stars, we can eliminate the starter motor. That's good!



Now from here there are a couple things.



When a battery goes bad, what happens is that it builds resistance, and becomes almost impossible to charge. The current provided from the alternator is not strong enough to overcome the resistance and it can't charge the battery.



If by chance, you called a tow truck, the charge they provide is much stronger than the charge provided from your car's alternator. This is why the battery may have been charged even though it needs to be replaced.



If this is the problem, what happens, is that after the battery is charged, your car will start up fine, and everything works. But your engine, lights, radio, and anything else is running off the battery, and your alternator is not able to charge the battery. When this occurs, as soon as the battery is drained, the car just dies. This is what you experienced.



Now with the alternator, this is easier to explain. It simply is not charging the battery. And once again, the same thing will happen. Once the battery is drained, the car will just die.



The difficutly is that you don't know what the source of the problem is. Is it the battery, or is it the alternator?



Typically, you test the battery first. It's easier to pull from the vehicle, it's easier to test, and takes a lot less time.



Now with this, when purchasing a new (or rebuilt) alternator, it's not unusual to get a bad one. Although this is a frustrating problem, it's not the end of the world. You just take it back to where you purchased it from, and they replace it, no problem.



So at this point you don't know if it's the battery of a bad alternator.



I'm sorry, but I think you should start from scratch. Have the battery tested before you take the alternator back. Once they test it, you will know if it needs to be replaced. If it does, then you have solved your problem. You just pop the new battery in there.



Good luck, and I know it doesn't help, but we've all been there!
I have changed the alternator on my 1990 Buick Park Avenue and it still has to be jump started. Why?
It could be that the battery can't hold a charge any longer or just a faulty regulator switch. It can also just be a faulty ground wire. Look at the posts of the battery and check the connections, if they are badly corroded, clean them to ensure that you have a proper circuit.
apparently the battery is shot, get it checked out at autozone, it might have a bad cell in it.