Can anyone help me out. I bought a new battery for my 98 Cherokee and the thing is always dead. I was told it was the voltage regulator so I went ahead and replaced it with a unit bought from flagship. Issue is still happening! I took a volt meter and measured battery with vehicle on and meter reads 14 volts but as soon as I shut the vehicle off it drains from 14 volts down to 9 volts? Can anyone give me some suggestions as to what to look at and test? Thanks in advance.

 

Step one would be to have the battery tested. Any auto parts store will do this.

Step two would be to perform a parasitic draw test to measure the current leaving the battery when the vehicle is off. If this test shows normal results then it really points to the battery being bad. If this test shows a value like > .5 amps you can be sure that something is pulling a lot of current on that battery (even when the vehicle is off) and it will need to be identified an corrected.

Based on how quickly you said the battery goes from 14v (while running) to 9v (while not running), that would imply that the battery is not charging up as it should. It implies that the charging voltage from the alternator is good, but that they battery isn't getting that voltage, or isn't doing what it should with that voltage. It could also be showing that something is putting a rather large load on it (it would have to be a big load, because even your starter doesn't knock a good battery down to 9v while its rotating the motor).

You could probably perform a voltage drop test between the positive output of the alternator and the positive battery terminal to ensure that connections between those two items are not causing voltage to be lost between them. That could definitely produce this type of behavior.

Are you able to start the vehicle on just 9v? That also seems odd. Or are you jump starting it?

 

Actually, step one would be to post in the Cherokee Technical forum, instead of the Chat forum.

 

That's right where it is!! How'd that happen?