2dusty23

I have a 1999 F150 (4.2l). A couple of days ago my battery died and I replaced with a new one. Then yesterday, I noticed my battery gauge getting lower while driving and the battery lite came on. Then everything went dead. I had it charged but, it is not holding a charge. Can someone tell why this is happening (alternator / regulator or something else) and how I can check to determine what the problem is.

Cheers!

Johnny Mullet

Hook a voltmeter to the battery and monitor the voltage while the engine is running. Turn on the lights and blower fan and other electrical items and watch the volts. The vehicle should hold a minimum of 13.6 VDC and if it lower, then it needs an alternator.

2dusty23

thanks for the info...I'll check it out. The battery must be fully charge to get a proper ready...right! If I get a reading of 13.6 or more am - I guess I will be looking for some other electrical problem?

Cheers !

thefonz

As suggested, check for proper voltage under running condition with multiple accesories on. If voltage is at least 13.6, the alt is doing its job. Make sure your connections are good. Also, just because the battery is new, doesn't mean it is good.

2dusty23

Finally, the battery is fully charged and seems to be holding a charge. However, the battery light is still on - why would this be happening.

thanks for the info...

Cheers!