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    VWVortex


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    Thread: Need help setting up digital multimeter for parasitic drain

    1. 08-22-2012 07:47 PM #1
      I have a 2003 VW Jetta GL 2.0 with a parasitic drain of 290-300mA . I recently bought this multimeter from Harbor Freight:

      http://www.harborfreight.com/7-funct...ter-69096.html

      I have never used a digital multimeter for the purpose of diagnosing a parasitic electrical drain in a car. The only thing I need help with are the proper settings on the multimeter for this particular purpose. You can see a picture of my multimeter by clicking the link and zooming in. Since I’m going to be measuring in milliamps, what position do I put the dial in? I’m guessing that I would set the dial to 20m under the DCA category ( 3 o’clock position) but I’m not 100% sure. With the leads, I have black negative lead in the “COM” outlet and the red positive lead in the VΩmA outlet. Do I have the leads in the right outlets or no? If not, what is the right way? I would really appreciate help with this. I do not want to destroy this meter simply because I did one thing wrong. Thanks in advance.

    2. 08-23-2012 10:30 AM #2
      Is that the right setup or do I need to change anything?


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      08-23-2012 11:04 AM #4
      You are on the right track. However, since you have an unknown parasitic draw, I would suggest you start on the 10A setting. Your 200mA setting has a fuse to blow at 200mA (.2 Amp), which will most definitely be blown in your case right off the bat. So red lead into the 10A DC port and the black into the COM.

      1.) Disconnect your negative battery terminal.
      2.) Place your meter IN SERIES with the NEGATIVE terminal on the battery and the disconnected battery cable
      3.) Find a way to either close your hood or at least close the hood-switch.
      4.) Remove any car chargers, lock all doors with key fob
      5.) Watch meter. Amps will jump around quite a bit but should settle down BELOW .2A (200mA) after 10-15 minutes on your Jetta
      Last edited by tip; 08-23-2012 at 11:09 AM.

    4. 08-23-2012 05:01 PM #5
      Quote Originally Posted by Noah Fecks View Post
      Look, I did not ask for smartass comments. Before I posted on here, I did several google searches but I did not find instructions specific enough for my purposes. A lot of guides talked about general multimeter uses, but did not give instructions specific to diagnosing problems in cars. Second, a lot of the multimeters used in the instructions tended to be Flukes used by professionals. Obviously, a $200 Fluke has greater capabilities than this multimeter that I purchased for $3.99 at Harbor Freight. Did you ever consider that? I do not want to destroy my multimeter by doing something that it can't do. Rather than spending 2-3 hours looking up information specific to my meter, I figured it would be faster to ask experienced users who can give and answer in 30-90 seconds.

      Quote Originally Posted by tip View Post
      You are on the right track. However, since you have an unknown parasitic draw, I would suggest you start on the 10A setting. Your 200mA setting has a fuse to blow at 200mA (.2 Amp), which will most definitely be blown in your case right off the bat. So red lead into the 10A DC port and the black into the COM.

      1.) Disconnect your negative battery terminal.
      2.) Place your meter IN SERIES with the NEGATIVE terminal on the battery and the disconnected battery cable
      3.) Find a way to either close your hood or at least close the hood-switch.
      4.) Remove any car chargers, lock all doors with key fob
      5.) Watch meter. Amps will jump around quite a bit but should settle down BELOW .2A (200mA) after 10-15 minutes on your Jetta
      With the dial, the 20m setting under DCA is the right one, correct? Since my particular parasitic drain ranges from 290-300mA, you are saying I should just avoid mA altogether and just use the 10 ADC setting for the red lead? Also, do you know if there is any special clip or attachment I can purchase to keep the leads connected to the battery terminals? The leads that came with my multimeter are the large needle-like ones. With my car, I doubt it's going to go below 200mA because this parasitic drain is fairly consistent.

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      08-23-2012 05:33 PM #6
      The 10A setting on the dial is the one you want. On most meters, it will block all lead ports except the correct ones, not sure about that meter.

      Since you said you have a 290 - 300mA draw, it will easily blow the fuse (note 200mA max below the port). If you put it on the 10A setting, it won't be as accurate, but you will see a reading in Amps instead of milliamps, (.29 - 3A in your case).

      Most meters come with alligator clips... I'm sure you can get them at radioshack. Or else rig up some way to keep them attached. If they fall off you're starting all over again. Good luck

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