This a Good Test for Electrical Shorts?

[jlevie]

When you connect the meter, there can be electronics in the car that draw considerable current as they power up. To avoid that surge from affecting the meter use a jumper cable to bridge the gap between the battery and ground lead that you remove after connecting the meter.

[rkettner]

there is some solid advice in this thread.

[jalopi]

FYI - if you're looking for a draw, try not to open the doors, work the windows, ect... pretty much anything. Many things will pull too many amps for your meter to handle, which will result in many blown fuses. If your meter reads 0mA when trying to test for a draw, you've either got a bad fuse or a completely stone cold dead car battery.

[Aleman]

Thanks for all the great advice! Here's a summary of what you need to do to track down a draw/drain on the battery:

1) Open the trunk and remove the bulb from the trunk light (unless you have a 'vert and your battery is in the front). Close all car doors, remove the key from the ignition, make sure to turn off the radio if the power is not switched to the 'accessory' key setting.

2) Switch your multi-meter to the 200m setting. Disconnect the negative terminal of the battery, and connect your multi-meter positive lead to the grounding cable. The negative lead goes to the negative battery terminal.

If you get a '0' reading, you have a blown fuse in the MM. Replace the fuse and try again.

If the initial reading jumps, then returns to zero, follow jlevie's advice:
When you connect the meter, there can be electronics in the car that draw considerable current as they power up. To avoid that surge from affecting the meter use a jumper cable to bridge the gap between the battery and ground lead that you remove after connecting the meter.

I used this jumper cable method before connecting the meter in the picture below.

NOTE: You should also consider setting your MM to 10A ADC mode to see if you get a reading on a larger scale. Be aware of where your red wire is plugged into the MM. You'll have to plug it into the 10A hole. The negative plug stays where it is.

After breaking 3 or 4 replacement fuses, I was still getting some strange readings on the MM. At wits end, I just put in a bigger capacity fuse, so it wouldn't snap immediately. Using a bigger fuse than recommended may damage the MM, but that was the only way could get steady readings. (My MM is old, so if it got fried, no big loss. It still seems to work OK).

About 20mA is a normal draw.



3) Once you get a steady reading on the MM, go to the fuse box, and pull the fuses in groups of 4 or 5 at a time, getting a new reading from the MM with each group. When you find the group with the biggest before/after reading difference, you can focus on that group of 5, pulling the fuses one at a time until you find the circuit with the problem.

4) Once you know which circuit is faulty, you can inspect that circuit closely for damaged wires or corrosion. Chances are good that the issue is with something you have tampered with recently. ;)

5) Once you figured it out, check the battery voltage level regularly with the MM set to 200V DC. I checked mine daily for a few weeks, and my reading went from 12.6 initially to 12.4 after one week of not starting the engine or trickle charging.



My issue turned out to be the seat heaters. Once I unplugged them, the battery drain stopped.

Fuse Charts for reference:








BIG BIG THANKS TO EVERYONE WHO CONTRIBUTED WITH GREAT ADVICE!









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