If you are using a multimeter set it to read current / amps. You may also need to use the "common/A/I" and "current" leads as opposed to the "common" and "voltage/V" leads on the meter. With a battery drain it only takes a few milliamps to cause a problem over time. If you have an autoranging meter just use it's standard current setting. If you need to select I would recommend a lower range (100 mA); with a 1+ Amp setting you may miss a small drain.
Arde's approach will help you narrow you search. Make sure the ingnition is off and hood, trunk, and doors are closed. If, like me, you need to have the drivers door open to work near the fuses make sure the interior lamp is switched off. If you can't find a current drain going through the fuses you might also remove one of the battery leads and check for current flow (with ignition off) between the battery and the lead - I would probably do this first to convince myself that there is a drain outside the battery. There are also a few very unlikely posssibilities beyond things which flow the fuse box.
If you were working on the wiper motor you may have bumped something around the hood light. There are not too many things "on" when the swtich is "off" Some quick "always powers" things to check are:
- Trunk light / switch
- Glove box light / switch
- Hood light / switch
- Is your clock working? Normally they will fail without a short through...
