I have been racking my brain as to why my battery keeps going dead. I have narrowed it down to a continual draw or short. With the positive battery cable disconnected when I put a test light between the battery and the cable, the test light glows bright and then slowly goes out. If I wait a few seconds after taking the test light away and put it back on it lights up again. I have pulled all the fuses, no dome lights are on, the trunk latch and light are disconnected, the alternator is disconnected (but I did accidently short it), I unplugged every relay I could find, and made sure the key was out. The key reminder buzzer doesn't work now and I think I removed it.(rectangular black cigerette pack sized thing under right leg area next to the flashers?) Any help would be great.

thanks

 

Don't forget to pull the bulb for the underhood light when checking for parasitic drain. Use a current meter and measure standby or parasitic draw with everything OFF, doors closed etc. it should be around 12-15ma, or .012-.015 amps. More than that is bad, pull fuses one at a time until the draw is gone then troubleshoot circuit. If you suspect the alt, disconnect all wires then recheck for draw. Significant change indicates fault within the alt.

 

The hood light is disconnected, all the fuses are out. I will see what the current draw is and let you know what it is.

thanks

 

Relays can get "sticky" when they get old. For instance, sometimes when you turn off your vehicles engine, part of the fuel injection system may stay engaged because of a relay that intermittently sticks in the "on" position.

 

I am veeery curious as to the outcome of this one. I've had this type of draw for 2 years now with no solution. I've even had a professional look at it, and he basically said "you'll have to replace the whole system. I can't figure it out." Yeah right, like I can find a brand new harness anymore. GM does not carry it, and aftermarket people don't make them yet.

 

Find another so called professional, he doesn't know what he is talking about. That's like replacing an engine because of a bad plug wire. A decent multi-meter is a must and a fundamental knowledge of how to use it is all that is needed. With the meter in the current mode remove one of the battery cables and insert the meter in "series" with the loose battery cable. Standby draw cna be measured that way. One by one pull each fuse in the fuse panel then simply look to see when the drain diminishes.

 

Okay I have narrowed it down to something in the acc. fuse. I thought I checked all the fuses, obviously not. With the acc. 20 amp fuse out I have no draw. The owners manual says this fuse controls the dome lights, hatch release, and a couple ohter things. I have a door off because I'm painting it but all of the dome bulbs are pulled out. Will there still be a draw somewhere even with the bulbs removed?

 

Do you have the Factory radio still?? If so if the clock is on at all times?...there is your draw. I have relaced over 1000 of these GM radios in my buisness. So if the radio clock is on, that is almost 99.9% sure that is your problem...Hope this helps?

Only other thing I can think of is a interior light , like inside the counsel.

 

put an vom on the battery and measure current coming off the battery to the car.. pull fuses till it stops, you can narrow it down from there, a helper makes it easy (so you don't get a reading from the interior lights pulling current)

 

A wild guess here, but check that the power switches for your drivers seat adjustment are in the middle (off) position. I've had exactly the same problem as you describe, & have been caught out twice with the drained battery. Once on my 84 Camaro, & second time on my 85 Transam. The switches are easily knocked when getting in & out of your car. Have a look anyway.

 

Did you fix your flat battery problem.?
Also just cos there is current draw from the Acc fuse it doesnt mean thats your problem. You will always have current drain there from the radio etc or from your alarm. Its only a problem if its excessive. The other thing is the battery can have a shorted out cell, this will cause current drain within the battery even with nothing connected. The best way to check is disconnect the battery and let it sit for a day or two. If it has that problem it will drain internally and be dead flat in 2 days. Also another way to check for this problem is to check the charge current going to the battery when the car is running, use a amp meter or another easy way is to pysically grab hold of the positive cable from the alternator to the battery. If the battery has that problem you will find this cable warm to hot as your alternator is trying to charge a battery with an internal short and this will heat up the cable. I hope this helps, dont assume that the battery is good, even new batts can have shorted out cells.

 

I did leave the battery disconnected for a week and it held up fine. I haven't checked the actual ampreage draw yet but the test light is very bright then slowly goes out. I have the acc. fuse out now and there is no problem with the battery maintaining a charge. That particular fuse also operates the horn relay and since I have the engine compartment wiring harness all unwrapped I have been using new convoluted tubing and routing everthing properly, so this process has been slow.

 

I will only ask this one more time...

Do you still have the stock radio?? If so, does the clock display remain on all the time?? If it does, there is your draw. Plug everything back together and leave the radio unplugged and see what happens. It is a common problem that alot of people over look.

 

The stock radio draw is a good tip. It was one of the reasons why I took it out when I bought my car. It did stay on, and it was an excuse to tell my Dad that I could justify the new unit.

Now, some 15 years later, I've gone through several stereos! AHHHHH, testosterone.

Has there been any issue with the coolant fans shorting a circut and causing a draw? I've found a bad motor in one of the fans and it seems that, from the tests, that circut is the one with the draw. ...so much for the "professionals" I hired.

 

I'm sorry for not answering about the radio. The clock does not stay on. When the key is off you can push the button in and the clock will display for about five seconds and then goes off. As for the fan I have already unplugged it. I will disconnect the radio though maybe something is wrong with it anyway.

 

I now doubt it is the radio, cause the display does go off. Hmmm You can try is still, but...

 

I would really check to see how many mAmps it is pulling. (slowly goes out) is how it should be. It take more juice to 'charge' those items that do stay on. The constant pull on the battery is what you want to find. 15mAmps or below is a good number. I just redid a bunch of my wires and it pulls 8 mAmps. But, for a second or two it pegs the guage. Once you get a guage on it 'pulling one fuse at a time' method works well to start with. As well as unhooking the alternator, electric fans, relays, etc... Until you find the one that is drawing the power.

 

I had similar problems it turned out to be my hatch pull down. THe thing was reaching max torque on the motor but not shutting down. This has a fuse beside the fuse block (its a inline) pull it out and see what happens. I would of never figured it out except I heard a click one day.

 

Well I found out what the draw was. It ended up being the radio anyway. I had a stcok radio out of a 89 Chevy van in it so I put my original radio in it (left channel doesn't work), and now I have no draw. Many thanks.

 

Well that is what I thought it was, but who cares! It's fixed and that is all that matters right? Glad ya found it!

 

My son 86 firebird has the same problem with a 12.6 volt draw with everything off. I know from previous experience that it should be below 5 volt. I went thru and pulled fuses and relays, that didn't do it. The radio isn't stock and the memory didn't change voltage draw. We even unplugged the rear hatch motor and nothing. Any suggestions? My next step is going to be going thru the harness and checking for melted together wires. That's a job I'm not looking forward to.

 

Try taking out the fuel pump, coolant fan relays driverside firewall behind and to the side of the brake booster. Sometimes the relays will come on and off when they start to go bad.

 

Thanks Aviator for the reply. I'll check that tomorrow, the flu is hitting hard here. I'll let you know if that's it. He just got his license and now the word DRIVE, has a whole new meaning...LOL

 

So did you check the drivers seat adjustment switches are not jammed or stuck ?

 

You could still have a bad battery. You're always going to have some draw, from the radio memory, securty system, etc. I had this problem with my wife's CAdillac for months. I was baffled. I replaced the battery and it hasn't happened since! Matt

 

Ok my question is my alternator keeps burning up and you said that if the batery is bad that cable gets hot, well this cable on the conector on the back of the ALT. gets to a point where i cant tuch it. then the alternator stops charging and if i move the connector in the back reall hard it sometimes comes back on for a few minutes, then dies again. what could this be? ive gone through 3 alternators

thanks