are you running any aftermarket lighting or stereo equipment directly off the positive terminal of the battery? if so, that would be the problem if not wired to turn off with the ignition.

 

Put a conductance tester on the battery first. Autozone should have one under the Midtronics name. This will give you an idea of battery condition, which could be part of your issue. I've seen new batteries have similar issues of not holding charge or maintaining CCA's unless "hot charged" (very recent charge of high amps).

Next, you need to chase parasidic draw. As mentioned by ATX, check all of your "aftermarket" stuff first. After that, it is a crap shoot in chasing down shorts.

 

I had thought of that, too.

Thanks. That would be a logical cause, but no, there are no aftermarket accessories.

 

check to see if the light under the hood goes out, mine kept staying on and draining my battery

 

Pull your fuses.. Pull one then recheck that spark, still there? put that one back in and try the next one... This will be SLOW but it will help isolate which circuts that you need to trouble shoot.
Do them ALL.. dont stop at one that seems suspect, do them all and write down the findings for each one

 

Because the computer(s) and clock stay hot all the time there will always be some load on the battery there may be other that stay hot too. You will need to pull there fuse first then try your hit and miss testing. It was never a good idea to keep powering up and down your computer in this manner anyway.

R Robinson

P.S. Some of the new radios don't like it to.

 

I have a new battery in my 1990 Cherokee Pioneer

You don't say how new, and whether it ever held a charge. Because "new" batteries sit on the shelf for who knows how long, it may have been marginal when you put it in. Get the place that sold you the battery to fully charge it. A fully charged battery should read at least 12.5 volts across the terminals.

and Auto Zone tested the alternator saying it is good.

I'm assuming that they meant that it will provide 14V to the battery when the engine is above an idle. That doesn't mean that the voltage regulator on the alternator isn't bad; it could easily be the source of the major parasitic current draw if there is one. I'll tell you how to check for this later.

When I touch the negative connector to the battery post with the ignition off and all doors closed, there are small sparks visible as contact is made and broken.

As others have said, there will be a parasitic draw from the clock, the computer, the radio, and other things. It should be low, under 50 mA. To test this, you'll need an ammeter and an assistant. The ammeter needs to have a 1 Amp range, or you risk blowing it out.

Start in the 1 Amp range. Put the wires of the ammeter between the disconnected negative battery cable and the negative terminal. If it hardly registers, switch to the 250 mA range. If it's below 50mA, the problem is not a parasitic draw. If the initial measurement is high, disconnect the alternator and try it again. If it's low, the problem is likely to be the voltage regulator on the alternator. If it's the same, start pulling fuses until the current drops.

Read the instructions that come with your multimeter/ammeter carefully. Most can't be used to measure current (amps) for very long at a stretch.

The problem with your idea of how to test is that a voltmeter, test light, or sparking will show current flowing because of things like the clock. But that shouldn't be nearly enough to run down the battery overnight.

The suggestion that you should pull fuses is flawed in that parasitic current draw can come from several circuits. So you can't pull one fuse at a time unless you have an ammeter to tell you which circuit the excessive draw is coming from.

If you don't have an ammeter, a multimeter with a decent one will cost $40 plus. It might be worth your while to take it to a good auto-electrical place and let them troubleshoot.

88Chief

 

You could also use a test light. Pull the negative battery cable off, hook the clamp end onto the battery, and the probe end onto the neg. cable. If you have a serious drain, the light will be bright. Start pulling fuses until it gets very dim and you've found the winner. The clock and radio use only a tiny bit of current, so it will stay dimly light until you pull those fuses out.

 

For what it's worth, shortly after I bought my Jeep in '99, I had a Kenwood CD player installed. Thereafter, the Jeep seemed to crank slower in the mornings... I left it sitting for the weekend and on Monday morning the battery was stone cold dead.

I had it towed to the shop and the mechanic traced the draw to the radio. Apparantly it was still drawing power (equal to leaving the radio on) even though the power was switched off. Now I have to remove the face plate to prevent the power drain.

Just a possibility...

 

all autos have some parasitic draw from radios and constant power accesories. these total anywhere from 1 thousandth to 25 thousandths of an amp. for somthing to kill your battery over night every night it would have to be the equivilant of a light bulb output which would be 3 amps or more. if your not versed in a using a multimeter just bring it somewhere and have a draw test done, or buy a book and learn how. its not for the novice. you will need to let all accesories on the truck power down over a time period of 5-10 minutes and have the ground terminal off you battery and use the multimeter inline to finish the circut. after about 5 minutes all non constant power accesoriues will power down and then you can find if you have a draw. the easiest way to find it after that is to pull the fuses one at a time and see when the draw stops. then trac that circut untill you find wich accesory is the cause. it can get involved since some circuts power more then one accesory. you can not open the dorr or turn the key or anything thAT WILL POWER UP EVERYTHING ELSE OR YOU WILL BLOW THE FUSE IN THE METER IT SELF AND HAVE TO START ALL OVER AGAIN. oops sorry hit the caps button


ideally a draw of .10-.07 is ok