Battery good new alternater bttery wnt stay charge

Not good to pull cable off batteries to test alternators an yes could be alternator or u may not have power to the alt.meaning the wire on top of alt or may havy bad plug wire boyh easy to check

sounds like your alternator is not charging the battery. with vehicle running take measure the voltage of the battery f it is higher then 13volts it is charging. if you do not have a volt meter remove the ground cable while the vehicle is running and the vehicle should stay running.

Just cause its a new alternator does mean it should work. I would check the charge when running cause it could just be a bad alternator.

Take it to a mechanic.

sounds like your alternater is not fixed. Your car ran off of battery power till you drained it. Complete alternater repair and charge battery. You can check if your alternater works by starting car and disconnect positive cable if it stays running your alternate is fixed. Shut car off and replace positive cable.

If the vehicle stalls when you pull the battery cable loose from the battery the alternator can not be good because the car would stay running. You have an issue with the charging system, Possible voltage regulator which is in the alternator. Have the alternator taken of the van and tested a the parts house.

First tell me why you don't think it's charging.
Because of the voltage reading you are getting at the battery terminals? The range you want is between 13.6v to 14.2v. The higher the voltage the lower the amps. and true the other way, the lower the voltage the higher the amps. If you get a reading of 13.6v or lower, the alt is nearing or at max output. An alt can only run at maximum for around fifteen minutes and it will start slinging solder from overheating. It's a good indication the battery is either totally dead or junk. Charging above 14.2 the alternater is running wide open and is only putting out high volts which will cause the battery to boil , in turn destroying it. This is a bad alternater. All alternaters have integrated voltage regulater with the exception of ver few of the earlier ones. You cannot test an alternater by removing a battery cable to see if the engine keeps running without taking great risk of damaging the alt, regulator. So tell me why you feel it isn't charging. Remember an alt is not made to charge dead batteries. Their sole function is to maintain the battery charge. Without a battery, the alt won't last 10 seconds.
Hope to hear from you and good luck.

If you have checked the battery, alternater, fuses and relays, it could be a faulty earth. Alternater may be faulty, there is a very good chance your fan belt may need tightening, your fan belt should not be too slack as if it was slack, it would not charge the battery properly and thus cause the battery light to stay on, if you push down on the belt it should move a little, but hardly much, if it is slack you may also get a squeal especially in wet weather, I would reccomend that you replace the fan belt. This is not expensive especially if you do the job yourself.

difficult to accurately *****, you need to get the charging checked, even though you have a new alternater the problem could be as simple as the charging light not working, which causes the alternater to initiate. or you may have an electrical component staying on draining the battery.

Mazda Mpv 2000 I also have the same problem, the alternater is testing good- 14.12Amp, so what is the problem the battery light will not go off.