Sweet64rivi Posted November 10, 2019 Share Posted November 10, 2019 ISO help trying to figure out what is draining my battery. My 4 year old battery went dead so I bought a new one. Car turned over and ran fine. Battery had a full charge when I parked it but was completely drained in a week. Any idea on what i should look for that could possibly be draining my battery? Link to comment Share on other sites More sharing options...
KongaMan Posted November 10, 2019 Share Posted November 10, 2019 Pull a battery cable and put an ammeter inline. Note the current draw. Pop out fuses one at a time until the draw drops. Remember that the clock is always drawing power; you might want to pull that fuse before you take the initial reading. Also, make sure that the ignition switch was in the LOCK or OFF position when you pulled out the key. 1 Link to comment Share on other sites More sharing options...
telriv Posted November 11, 2019 Share Posted November 11, 2019 ALSO don't forget the courtesy lights. Link to comment Share on other sites More sharing options...
RivNut Posted November 11, 2019 Share Posted November 11, 2019 Someone in the past figured out that when a passenger was exiting the back seat, the switch for light in the rear of the console got turned on. Maybe your glove box door won't turn off the glove box light. KM has the procedure. Link to comment Share on other sites More sharing options...
KongaMan Posted November 11, 2019 Share Posted November 11, 2019 Might also check your trunk light. Kinda hard to see from the outside, though (unless you pull a taillight); maybe the wife will consent to climbing in the trunk and letting you close it. Link to comment Share on other sites More sharing options...
telriv Posted November 11, 2019 Share Posted November 11, 2019 If the trunk light stays on for any amount of time just put your hand over the spot where the light is & it will be warm to the touch. Link to comment Share on other sites More sharing options...
Seafoam65 Posted November 11, 2019 Share Posted November 11, 2019 Also, if you have a power seat, the power seat switch is a prime suspect. To find the drain, you need to disconnect the negative battery cable from the battery and put a test light or amp meter between the disconnected cable end and the battery post. Disconnect things that have power with the key off until the test light goes out or the ampmeter reads zero amps. The component that you disconnect to make the test light go out is the source of your drain. Link to comment Share on other sites More sharing options...
telriv Posted November 11, 2019 Share Posted November 11, 2019 I had a '63 one time that would drain the battery, sometimes overnight. The way I found it was to disconnect the neg. terminal & then touch the cable to the post. I could hear a clicking noise. Turns out when someone wired the car instead of putting the power wire to a keyed source it was connected to a source of power all the time which would drain the battery. ALL the suggestions offered are relevant. You NEED to start somewhere as NOBODY has a magic wound to help figure out a problem over the internet without being there. Again, my nickels worth. Tom T. Link to comment Share on other sites More sharing options...
johnrex Posted November 12, 2019 Share Posted November 12, 2019 A bad or leaking diode in your alternator can cause a drain. Check and see if you alternator voltage is lower than normal when running. 1 Link to comment Share on other sites More sharing options...
Hazdaz Posted November 13, 2019 Share Posted November 13, 2019 Obviously finding the drain is your best solution, but do consider adding a kill switch to your car. Even if you have no battery drain, its a nice safety/security thing. Link to comment Share on other sites More sharing options...
Bloo Posted November 13, 2019 Share Posted November 13, 2019 All good advice, but I always start with the method KongaMan posted, moving on to some of the other ideas if necessary. I use a test light instead of an ammeter (multimeter) at first, to make sure I'm not gonna blow the fuse in the multimeter. Then if the lamp only glows dimly or not at all, I move on to the ammeter (multimeter). In addition to the trunk light, check the glovebox light if it has one. Any bulb you cant see is suspicious. As for the clock, if it is the "Borg" style usually used back in those days, it shouldn't be a constant draw. It should just pulse now and then. If it is a constant draw, the points are stuck and you probably just found the issue. Even though the clock doesn't draw constantly, every little bit runs the battery down some. Cars with clocks run the battery dead faster than ones without, and a old car with a mechanical voltage regulator and no clock should have no current draw at all. There is only the self-discharge rate of the battery to worry about. That is a good argument for pulling the clock fuse, or getting a battery disconnect switch. If you need the clock to work, maybe a battery maintainer. 1 Link to comment Share on other sites More sharing options...
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