Electrical Problems

Something is draining the battery of my van when parked for a duration of time. Can’t seem to pinpoint it. This is not my everyday vehicle so I am trying to tackle the problem in my spare time. Since spare time is hard to come by these days, I have been disconnecting the battery when the vehicle is parked. In doing so; am I draining the battery by connecting and disconnecting every time I plan to move it?

And, If I just have one terminal of the battery connected (when not in use), could this drain the battery as well?

First off, has anything aftermarket been added to the van that uses the electrical system?
If so, disconnect that, and see if the battery drain ends.

If not, then the only recourse is to use a multi tester, and start pulling fuses to see which circuit is the biggest draw on the system, adn then follow that wiring to the source.


If only one terminal is connected there would not be a path for current flow hence no discharge would occur. Check in the dark for glove box lights ,make up mirror lights, dome lights and brake lights. Also check power antenna,ride control pump, cooling fans and any added accessories such as TV’s inverters,cd-dvd players if it is a custom van. An easy way to spot a major drain is to hook a tail light light bulb in series with the battery, if there is a major drain the bulb will light. Then you can remove fuses one at a time until the light goes out. Next read what the fuse is for and start eliminating items fed from the fuse.To put the bulb in series, in case you are not familiar with electrical terminology remove one battery terminal and connect one side of the light bulb to the battery where you removed the terminal from and the other side of the light bulb to the terminal you removed from the battery.You can buy a tail light socket and bulb at the auto parts store to make things easier, or if you have an multi-tester with an amp scale you can use that provided it has a high enough scale. Allways start on the highest range. Every so often I have seen an alternator malfunction where it will cause a drain when the vehicle is off but still manage to charge it when running. Hope this helps

Only, thing I can think of aftermarket is the radio which was installed about six years ago. I am going to try a multi tester.

Thanks, for the tip.
Have not tried the glove box. I’ll give it a go!