Wont Stay running?

[darkfiire5000]

I have a 1996 Jeep Grand cherokee 5.2L after it starts it dies and has to be jumped again to get it to start. Replaced the battery and it still does it any ideas, its driving me crazy   

[resq302]

Any symptoms prior to this happening such as check engine light on?

[firefighter3931]

Could be a bad voltage regulator ?    Is the new battery fully charged ? 



Ron

[darkfiire5000]

No check lights on or anything and yes the new battery was charged cause we charged it before we put it in just to be safe

[firefighter3931]

OK, how long after it starts does it die ? A fully charged battery will keep the engine running for awhile even if the charging system is non functional 



Ron

[darkfiire5000]

Found the problem it was the voltage regulator thanks a ton .

[firefighter3931]

Found the problem it was the voltage regulator thanks a ton .

[Steve P.]

NEVER trust idiot lights.. An inexpensive voltage meter is way better and allows you to make many tests.

A fully charged Battery should hold 12.4-5 volts. If you fire up the motor and it is STILL at the same battery voltage as before starting or AT LEAST 1.4 volts higher it is not charging properly.

[resq302]

General rule of thumb that I learned back from auto shop class in high school was that battery voltage with the car not running shold be 12.8-13.8 volts.  With the car running the battery should read something like 13.8-14.8 volts.  With the car running and the head lights on, battery should read something like 12.8-13.8 volts.  All running measurements were with the car at idle speed.

[GeneralLeeTESH]

A great way in addition to that in testing the battery/alternator to troubleshoot the problem-WITH the CAR RUNNING-disconnect the Positive (red) batt cable. IF the alternator is good and putting out 12-14 Vdc at idle, then you KNOW the alternator is O.K.. If the car dies-it's time to replace the alternator !

[Steve P.]

A great way in addition to that in testing the battery/alternator to troubleshoot the problem-WITH the CAR RUNNING-disconnect the Positive (red) batt cable. IF the alternator is good and putting out 12-14 Vdc at idle, then you KNOW the alternator is O.K.. If the car dies-it's time to replace the alternator !

On a PRE-COMPUTER car this is true..    DO NOT DO THIS on ANY VEHICLES WITH OBD1 or OBD2 computers. You can fry the works.....

[darkfiire5000]

GOOD TO KNOW THANKS