1999 Ford Taurus: Battery not holding Charge?

Battery loosing charge.
Both alternator and battery are replaced.But still the same problem.


On some cases its seen,then new parts also comes faulty.A bit of proper testing is required.Get your multi-meter and start proper voltage testing.


It sounds that you have a problem with your charging system. Please check for voltage at the battery terminals when your engine is running. You should see something above 13V ( usually 13,8-14,5V) otherwise you have no charge.
If you have no charge, then it either a faulty alternator or wiring issue.
Since you have already replaced the alternator, then mostly its a problem with wiring.But still new parts comes faulty.If possible try with another working alternator.

Follow this voltage testing procedure. This will tell which part is draining the battery charge and where the wiring's are getting short.
First of all make sure you have +12v battery power on the thick Yellow/White wire at the alternator ( use a test light connected to ground). If you don't get +12v battery voltage on this wire, then check the 175A mega fuse in the power distribution box.
If it is OK, then disconnect the two way connector from the alternator and check for +12 power on the Orange.Light Blue wire at the 2-way connector( use a test light connected to ground). If OK, turn the key ON and check for battery voltage on the LightGreen/Red wire at the 2-way alternator connector ( use a digital multimeter).

This testing details will help.
Thanks.

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