Car Battery Keeps Dying

kc0rkx_finch wrote: Two of my friends have had the exact same problem. my first friends had a defective amp that always stayed on evin with the fuse pulled. That was a wierd experience. I dont see how it did it but it did. My other friend had either a bad alt or one that wasnt strong enough for the system we never had a chance to find out he sold his truck. Heres how to find out though Try this at night. 1. Start the car. 2. Headlights on high 3. POUND The DAYLIGHTS out of your system. I mean drive it to the point of distortion, but dont blow the sub(s) and see if the headlights dim when the subs hit. In most cars they will a little bit thats normal. If they dim too much, rev the engine to approx. 2000 rpm, if they still do the same thing, your alternator dying. This test was recommended to me here at the 12 volt and by a mechanich friend. Try it.   see you l8ter.

OR You could go to the local parts store and have your alternator checked out. But that seems to logical.Certified Security Specialist

Always check info with a digital multimeter.

I promise to be good.

Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

I have been managing those kind of situation on a daily basis. First you need an amp meter and a full charged battery. then you will set your meter to the larger scale in DC Amp. If your meter is a wire style hook it up in the proper hole for amp meter and install this one in serial between the negative terminal of the battery and the negative battery cable. Black probe on the battery and red probe on the disconnected battery cable. If you are rich enough to own a DC clamp Amp. meter install this one around the negative battery cable. The maximum reading wich is allowed (by most of the manufacturer)is 30mA You will read 0.030 Amp. To find out the drain Remove and put back each car fuses one by one . Check the impact on the meter. If you dont want to burn the fuses of the wired meter type try to turn off the dome light by disabling it at the switch or at door switch before to start working on the vehicle. This is a good way to find hiden electronics devices in a car that is burning your battery power. As well as to find Boomerang 1 devices....! anyway ....

Montrealler wrote: The maximum reading wich is allowed (by most of the manufacturer)is 30mA You will read 0.030 Amp.

Actually that number varies manu to manu. For gm it is 50mA. Also you need to make sure that if your bcm shuts down that you let it before you record the reading, this can take upto 30 minutes. I will not comment on your boomerang comment except it is flawed.Certified Security Specialist

Always check info with a digital multimeter.

I promise to be good.

Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

By the way Boomerang 1 devices draw constantly between 35 to 55 mA. Boomerang 2 hide theirself for 15 minutes when power is tooked off the vehicle so it is possible to find boom 1 easily . Much harder to find boom 2 using the preceding way. For GM Saying,,, As seen on their web site for service there is the maximun draw current allowed wich vary in function of the RC(reserve capacity) of the battery Battery Electrical Drain/Parasitic Load Test Tools Required J 38758 Parasitic Draw Test Switch ( this one is a switch to quick disconect/connect) the battery power Diagnostic Aids    • Be sure to rule out any possible obvious influences, such as customer error or aftermarket equipment.    • Customer driving habits, such as regular short trips. This does not allow enough time to properly charge the battery. Refer to Battery Description and Operation .    • Verify that the battery and charging system are in proper working order. Refer to Battery Charging and Charging System Test .    • A battery discharging for no apparent reason while the vehicle is parked can be caused by an intermittent draw, such as a module waking up, or a continuous draw, such as a dome light or stuck relay.    • Some systems and modules such as OnStar®, and regulated voltage control (RVC), if equipped, are designed to wake-up, perform a task, and go back asleep at regular intervals. Refer to Body Control System Description and Operation in Computer/Integrating Systems for the system or modules description and operation.    • Remote keyless entry (RKE) will wake up due to an outside input. Refer to Keyless Entry System Description and Operation in Keyless Entry.    • Important: The battery specification listed below is a generic specification. Refer to Battery Usage when testing the battery. The battery run down time will vary depending on cold cranking amperage (CCA) and reserve capacity (RC). If the CCA and RC are higher, then the battery run down time would be longer. If the CCA and RC are lower, then the battery run down time would be shorter. The graph below indicates roughly how many days a 690 CCA battery with at 110 min. RC (60.5 AH) starting at 80 percent state of charge will last with a constant current draw until it reaches 50 percent state of charge. Differences in battery rating and temperature will affect the results. Current Drain Days 25 mA 30.5 50 mA 16.5 75 mA 11 100 mA 8.25 250 mA 3.3 500 mA 1.65 750 mA 1 1 A 0.8 2 A 0.4 Caution: Refer to Battery Disconnect Caution in Cautions and Notices. Notice: Do not turn the parasitic draw test switch to the OFF position with the engine running. Damage will occur to the vehicle's electrical system. Notice: The test switch must be in the ON position when removing the fuses in order to maintain continuity in the electrical system. This avoids damaging the digital multimeter due to accidental overloading, such as a door being opened to change a fuse. Important: The switch knob (1) on the J 38758 is marked ON and OFF. When the switch knob is in the ON position, the circuit is closed and electrical current will pass through the switch. When the switch knob is in the OFF position, the circuit is open and electrical current will not pass through the switch. Disconnect the battery negative cable from the battery negative terminal. Install the male end of the J 38758 to the battery ground terminal. Turn the J 38758 knob to the OFF position. Install the battery negative cable to the female end of the J 38758 . Turn the J 38758 knob to the ON position. Road test the vehicle and activate ALL of the accessories, including the radio and air conditioning. This may take up to 30 minutes. Park the vehicle. Turn the ignition switch to the OFF position and remove the ignition switch key. Connect a 10-amp fused jumper wire to the test switch tool terminals. Turn the J 38758 knob to the OFF position. The current now flows through the jumper wire. Wait 1 minute. If the fuse blows, install an inductive ammeter and go to step 20. Remove the fused jumper wire. Set a digital multimeter to the 10-amp scale. Connect the digital multimeter to the test switch tool terminals. Turn the J 38758 knob to the OFF position. The current flows now through the digital multimeter. Wait 1 minute. Check and record the current reading. When there is a current reading on 2-amp or less, turn the J 38758 knob to the ON position. The electrical current will now pass through the switch. Then switch the digital multimeter down to the 2-amp scale for a more accurate reading when the J 38758 knob is turned OFF. Turn the J 38758 knob to the OFF position. Wait 15 minutes for most vehicles. Check and record the current reading. Note the battery reserve capacity, amp hour rating. Refer to Battery Usage . Divide the reserve capacity by 4, amp hour rating by 2.4. Compare this to the multimeter milliampere reading taken in the previous step. The parasitic current drain should not exceed this number. Example: If a battery has a reserve capacity of 100 minutes, (60 A/H) the current drain should not exceed 25 mA. If excessive current drain is not found at this time and there are no other apparent causes, complete the following: Using the MIN/MAX function of the digital multimeter, monitor the parasitic drain overnight or during the day. This will determine if something has been activated during that time frame. Notice: The test switch must be in the ON position when removing the fuses in order to maintain continuity in the electrical system. This avoids damaging the digital multimeter due to accidental overloading, such as a door being opened to change a fuse. Important: Removing fuses, relays, and connectors to determine the failure area may wake up modules. You must wait for these modules to go to sleep or use the sleep function on the scan tool. When the vehicle has an unacceptable amount of parasitic current drain, remove each fuse one at a time until the current drain falls to an acceptable level. This will indicate which circuit is causing the drain. Refer to Power Distribution Schematics in Wiring Systems to diagnose exactly which part of the suspect circuit is causing the parasitic drain. In some cases a non-fused circuit or component, such as a relay, is the cause of excessive parasitic current drain. Repeat the parasitic current drain test procedure after any repair has been completed to make sure that the parasitic current drain is at an acceptable level. When the cause of the excessive current drain has been located and repaired, remove the J 38758 . Connect the battery negative cable to the battery negative terminal.

In my old 86 cavalier Z24 the system would cut out entirely if it sat at idle for more then 20 seconds or so. As soon as I reved the engine it would come back on. I took it to autozone and they tested the alt and said it was fine. Since it was a rebuild and under warrenty there (previous owner had bought it there about 3 months ago) they gave me a new one. After that one didnt work (they reclocked it to fit my car and it ruined the alt) I finally got a working one that worked perfectly. I junked the car soon after that becasue a rod was knocking, but long story short I wouldnt trust audtozone, pep boys, advanced auto etc. to test a alt. Most of the workers there dont know s**t.

So montrealler, who do you work for? Gm dealer?Certified Security Specialist

Always check info with a digital multimeter.

I promise to be good.

Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

Now I am back to car starter business. But I have been working for Boomerang. I am now dooing technical support for installers in a car starter compagny. This procedure is from GM Web site. If you need stuff from them(GM) Let me know. knightspirit&hotmail.com

I would have to say I THINK it is your alternator. I have had to purchase over 4 new batteries before i realized what the problem was. My lights also would dim when I hit the brake and heaedlights would dim aswell. I put on the new alternator and had no problems since with electric. (note: I had no other components hooked up to the battery at the time it was draining). take back the old one to get the core value and it should only cost you about 25-35 bucks.Note: get a second person to help you put it on because the belts make it somewhat difficult to do your self.wes strickland