Questions and Answers

Finding A Parasitic Electrical Drain Q. Dear Vincent, I have a parasitic drain in my car and I am currently trying to locate it. The general question I have is how should I hook up my multi-meter to the battery? The multi-meter measures AC voltage, DC voltage, and DC amps. I was trying to use it as an ammeter measuring DC amps (I hooked it up in series with the negative battery terminal) but it kept blowing the multi-meter's fuse.

The meter's fuses are 0.5 amp 250 V. Do you see what I'm doing wrong? Is the multi-meter not suitable?

Also, when I hooked the meter up the car was off and all the fuses pulled. I would start replacing the fuses and the meter would never give a reading. Upon inspection the meter's fuse would mysteriously be blown.

Thank you,
Joseph

A. The meter has to go between the positive battery terminal and the positive battery post. Like so:

You need a meter that will handle up to 20 amps DC, otherwise you'll blow the fuse and possibly damage your meter. If you have a meter with multiple ranges, start with the highest range and work down. Most digital multi-meter s are auto-ranging.

I don't know what make and model of meter you have, but it sounds like it's not up to the task.

Fluke meters are very good meters, but very expensive. If you look around, you can find a Fluke clone for much less. Some even have inductive amp probes that clip on around the batter cable. You don't need to remove any cables.