2007 mazda cx 7 battery light on and the battery is not charging I change alternator 3 times but still not charging battery get hot and is there any ground for the alternator which causing this o
Sounds like the battery has a short in it. Have the battery checked, probably needs to be replaced.
i have change battery but still no charging
I am not real familiar with that one, when you say the battery was getting hot is an indication of over-charging then if the batter is in good shape. The alternator is automatically grounded when mounted. I think there is a problem with the regulator. The battery getting hot = overcharging, light on the dash and overcharging is caused by the regulator. The regulator is either a separate unit, or it is in the alternator. So have you put a volt meter across the battery terminals to read DC volts? It should show 14.2 to 14.5 volts when charging.
it drains the battery power am suspecting the ecm is not controlling the alternator
The charging system is its own system that supplies power for everything. The only thing controlling the alternator is the regulator. To narrow down a draw on the battery you are going to need a volt meter. First off, take the neg. cable off the battery and check with the volt meter between the cable and the battery post, see what it reads. There is always some my-newt amount of voltage, should not exceed like .7V. If it does and you suspect the draw coming from the charging system, take the positive lead off the alternator, and don't let it touch ground. Keep the neg. off the battery while doing this. Now check between the neg. cable and battery post. If there was voltage, it show that it dropped.
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