My Festy's a battery eater

[therris]

88 LX 130k 5 spd manual

Just got it runnin at the end of January and put on a new battery as the old one was dead. Ran fine for almost 2 months then started getting some slow turning starts. Got the battery checked and it was bad. Asked them to check the alternator while on the car and the alternator came out fine. Got the battery replaced.

2-3 weeks later, car wouldn't start one afternoon. Had to push start it myself (love this car for this), took the battery back again and it came back again as bad. They tested the alternator at the same time and it was fine again.

However, when I got it started and disconnected the batt, I turned everything on (vent on hi, radio, lights, flashers) and the car would run but would cut off what it needed to stay running (radio wouldn't stay on, flashers wouldn't flash, lights went out).

Any guesses? I'm assuming the alternator needs a rebuild. I feel like it works fine but when the draw from everything puts more work on it, it starts skimping on running everything and recharging the battery to keep the engine running, eventually sucking the batt dry. But why does it keep testing as good?

[FestYboy]

never, NEVER remove the battery while engine is running!!!!!!!! you'll full field the alt and most likely toast it and festy alts are expensive!

[WmWatt]

You should be able to diagnose charging problems with a voltmeter across the battery terminals while the engine is running and the various devices you mention are turned on an off. I've seen voltmeters on sale for $10.

[scitzz]

Yeah, check the current, and also, check to be sure alt belt is tight, is it is loose, it will not charge as well.....

[Pu241]

Still could be crappy quality battery!
Where did you get it from and who is the manufacturer?

[therris]

Luckily the battery has been from NAPA, their 18 month free replacement battery. I'll check the belt tightness and connections at the alternator.

[miami man]

i just replaced my alternator and the cause was a bad battery..easy fix.

[miami man]

i thought mine was a bad alternator but it was the battery as someone here had said it was.

[SIBladerunner]

Check to make sure there isn't a parasitic drain on the battery, if the drain is too high the battery won't last long and it might not be dead, but just not charging enough. Make sure your terminals are good to and the cable going to the alt and the battery.

[jglutz]

Just a point to consider......
When you go to start the car, does the charge light on the instrument panel come on the go off? all of the lights should come on at this time the go out....normal lamp test function. If the light does not come on.....Hmmmm....the alt or corresponing circuit is shot and you don't know it. Just something to be considered.

All of the previous post are good and should be considered/investigated.

[therris]

The dash lights function normally. I guess I'll remove the alternator and have it bench tested. I'll go ahead and get the battery replaced too. Every time this has happened before the battery tests show that it has a bad cell. But I'm thinking a bad cell on 3 batteries in a row is a bit unlikely.

[jglutz]

Old battery test here.....turn on your radio and dial in an AM station....if you hear a lot of buzz and the frequency of buzz increases as you increase the engine RPM. The condenser is shot or some othe part of the ignition cuicuit is mal-functioning.

The point...the BUZZ is an eletrical transient that is not being properly suppressed. If this transient makes it to/thru the battery, it will cause a breakdown in the battery capacity.

[scitzz]

Old battery test here.....turn on your radio and dial in an AM station....if you hear a lot of buzz and the frequency of buzz increases as you increase the engine RPM. The condenser is shot or some othe part of the ignition cuicuit is mal-functioning.

The point...the BUZZ is an eletrical transient that is not being properly suppressed. If this transient makes it to/thru the battery, it will cause a breakdown in the battery capacity.

NICE!
You are a font of info, you know that?

[therris]

No, that's not the case. In fact the am radio won't come on due to not getting enough power, it will come one when the RPMs are around 2200-2800. Any higher or lower and the radio cuts off.

Blinkers barely blink, vent fan is crazy low. If I sit at idle and use blinkers or fan, the RPMs will adjust to keep the car running, but nothing else.

[jglutz]

No, that's not the case. In fact the am radio won't come on due to not getting enough power, it will come one when the RPMs are around 2200-2800. Any higher or lower and the radio cuts off.

Blinkers barely blink, vent fan is crazy low. If I sit at idle and use blinkers or fan, the RPMs will adjust to keep the car running, but nothing else.

Symptons say voltage reg/alt but the light on the dash does not illuminate....that's odd...unless the voltage reg is shot and not able to fire the lamp....or I hope your good w/ a voltmeter to start looking for a votage drop.....might be best to take the alt to a shop/store wher it can be tested.

Anyone, i dont have access to my shop manual...where does the other end of the large wire from the alt terminate...is it under the fusible link block....if so...I would douvle check for crud on the terminal.

Thanks scitzz.