Battery DYING!!! need help quick!

[1Alpine944]

ok so i guess i fix one thing then another arises.... i drove the car today w/o any problems and then i went to dinner when i came back batt DEAD!!!! the car would not turn the lights and horn and all would but NO TURN i got a jumper box and the car started w/o any problems... anyone knows what it might be?
i put a multimeter on the battery when the car is running and im getting 11.25v i did the same thing on my VW and the battery reads 13.45 when the VW is running could it be my alternator? what i cant understand is why does the car run if the batt is dead.. something is not charging i guess.

[Dantilla]

The alternator can keep the car running even if the battery won't hold a charge.

Try another battery, or at least take it to an auto parts store that can test it.

[1Alpine944]

Originally Posted by Dantilla

The alternator can keep the car running even if the battery won't hold a charge.

Try another battery, or at least take it to an auto parts store that can test it.

i did that already and the battery is good but when i put the multimeter on the battery while the car is running it reads 11.25 volts

[Gary2397]

Your alternator is bad and it is not charging . It is draining the battery.
When you put a multimeter on the battery when the car is not running, it
should at least read 12.5V. When the car is running it should read 13.5V or more
not 11.25V.

You should be able to see battery light lid on your dashboard while it is running.
Take the alternator out and have the store test it.
If you consider using the same battery, have the store recharge it .

[MrWrong]

I'm starting to sound like a broken record here.

It sounds like the armature on your alternator isn't being energized. It will energize itself, but only put out about 12 V when it does (sounds like your case), and this is really working the alternator (A bad thing).

On the early 944's the armature is energized through the idiot light on the dash. If this light bulb burns out it won't energize the armature and your alternator won't work properly.

The easy way to test this bulb is to see if it lights up when the engine is off and the key is in the accessory position.

After the bulb test make sure you have battery voltage at both the wires connected to the alternator with the key on engine off. The big wire on the alternator should be connected directly to the battery + terminal. The smaller one is connected to the idiot light which switches on and off with the ignition switch.

If both wires test out good then I'd look for an alternator.

[John_AZ]

A recent post:
http://forums.pelicanparts.com/showthread.php?t=444845

PEP Boys has the Bosch Group 41 on sale and $20 rebate (In AZ-Check your store).

GL
John_AZ
1988 924S + 1987 924S

[bearone2]

Originally Posted by Dantilla

The alternator can keep the car running even if the battery won't hold a charge.

Try another battery, or at least take it to an auto parts store that can test it.

the alternator can keep it running up to a point where the fuel pump stops working.

even if it runs the batt needs to be jumped or charged each time you drive it.

[John_AZ]

CAUTION! Whatever you do---NEVER run the car without the battery. You will distroy your computer and much more.

GL
John_AZ

[Dean924s]

I have run the car with out the battery in place and there were no ill effects to my car.

[Pops944]

The battery provides a reference for the alternator/regulator. Without it in the circuit it would be possible to reach an over-voltage condition that could cause damage to the computer parts. I'd say running the car at low rpm's while trouble shooting the charging system or starting system wouldn't cause a problem, but running at high rpm's most likely would.
If the battery tested good but you only have 11.25 volts when running, you either have a bad regulator or a bad alternator. I'd pull it and get it tested at a friendly parts store.