Richfiero

what would cause my alternator not to charge the battery and the battery dying after a half a day and the car to run a lil hesitant.

LS1mustang

1: crappy battery
2: alternator isnt up too par
3: Bad ground

88BlueGT

Check your ground, take your battery to Autozone and have the check it for you and if its not the battery than its the alt. There are only 2 things that can possibly be wrong.

sick95gt

Also, if you have deep cycled your battery(let it run dead) it will never hold the charge like it used to. Unless of course you have a deep cycle battert like an Optima yellow top

Richfiero

The battery is brand new because the old battery did not hold a charge at all. when it drained down I did the fast charge and when it drained down again i did the slow 2 amp charge. and the bat still drains after a day of sitting. the alternator is about a year old. and I ran A wire to the alternator to the neg side of the battery. and nothing happened. when I test the voltage of the battery when car is running it only says it is at 12.1 to 11.5.

Could there be a short causing the alternator not to charge the battery and make the battery die when sitting for a day?

86HOGT

Aftermarket alternator? AKA parts store one? Most likely the culprit.

90GTRagtop

If that is the voltage with the engine running, then the alternator is not charging at all. You don't mention the year, but I'm assuming it has an internal voltage regulator. Your problem could be the alternator, or regulator, or a wire, or a fuse, or a fusable link, or a bad connection. First check all of your fuses. If there isn't power coming from the battery to excite the field, it will not charge. If it's not a fuse or a broken or loose wire, get the alternator tested at a parts store. If it does have an external regulator, you may want to change that to test it.

Richfiero

it is a 92. the wires seem to be fine of what i can see. what links would have the fuses would it be in the fuse box or on a wire some wear?

88BlueGT

You should just get a new alt. Screw the hassle.

Richfiero

so if i get the one wire alt. what do i do with all the other wires that go to the alt now?