Battery Light???

[shoinoff95]

Today, started my car and started driving around. My battery kight was flickering on and off, but never got too bright like it was on all of the way. Then when I got home, my battery light came on-full light. At idle, the car kept missing out or maybe misfiring, but the light still wasn't on completely. I knoticed that when I reved the engine, the light came on fully??? I checked the battery, it was charged at least 75% and checked the battery wires they were fine. Any suggestions??? shrug

 

[SHO24V6]

May be your alternator is going out and when the light is coming on it means that it is using the battery for power rather than the alternator.

maybe, just my 2 cents boink

 

[projectSHO89]

Connect a meter to the battery post terminals.

Measure the voltage while the engine is running.

Normal reading at idle with a properly charged battery and a good alternator will be around 13.8-14.0 volts.

Below 12.6, the alternator is not charging and the engine will stop running as soon as the battery is discharged.

Over 14.5 or so, the alternator is overcharging the battery and will quickly cook it.

It sounds like either the alternator or the associated wiring is bad. You can remove the alternator and take it to a parts store such as AutoZone or Advance Auto Parts for free testing.

Steve

 

[SHOZ123]

How did you know the battery was charged at 75%. The only way to know this is to do a measured discharge to 1.75V per cell and figure the total amp-hour drain. Unfortunately auto start batteries do not have a total amp-hour rating. Only some convoluted, dreamed up CCA rating used for marketing purposes.

 

[shoinoff95]

I used a battery tester, where you suck up some of the battery fluid and count how many balls are floating, thus telling you how much charge your battery has. But my battery light ended up going off last night after messing with the plug wires on the alternator. But I am still going to get my alternator tested!!! shrug
Just got my alternator tested and its around 13.7-13.9 volts so maybe it was just someting with the connector plug to the alternator!!??

<small>[ February 19, 2003, 02:49 PM: Message edited by: shoinoff95 ]</small>

 

[shoinoff95]

Car was acting up again yesterday, and I can't figure out what is WRONG!!! shrug So I just made an appointment with my mechanic to get it in the shop Tuesday!! I will let you know what happens!!

 

[SHOZ123]

The tester with the floating balls is a cheap hydrometer which measures the strength of the acid. The fact that it showed a 75% charge could be from the battery being undercharged or too much water had been added in the past. A hydrometer is only a good tool for testing a battery when you know either what the reading was before you started charging the battery or when you know the battery is fully charged.

If you put your battery on a charger overnight to fully charge it, and the amps don't drop to less than 1, then the battery is bad.

A good alternator should read 14.4V or so with a full electrical load and at 1500 rpm.

<small>[ February 21, 2003, 09:39 AM: Message edited by: SHOZ123 ]</small>

 

[shoinoff95]

I did take my battery out yesterday and took it to AutoZone (where I bought it at about a year ago) to have it tested also. It tested ok with a full charge! So I am still thinking that it has got to be the alternator or maybe the voltage regulator?!