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  1. Join Date
    May 2017
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    2,098
    #1
    I just bought a clamp meter, and I am testing it on our 1990s Starex, is it better to use the clamp on the positive battery cable or the negative battery cable? What is the desirable milliamp range for a normal battery drain? Thank you.

    As of now the findings of my test found that my battery is discharging 1.2 amps on the negative terminal cable. Do you think I have to look for a electrician to find where is the culprit?

  2. Join Date
    Mar 2008
    Posts
    52,514
    #2
    Quote Originally Posted by Athrunzala View Post
    I just bought a clamp meter, and I am testing it on our 1990s Starex, is it better to use the clamp on the positive battery cable or the negative battery cable? What is the desirable milliamp range for a normal battery drain? Thank you.

    As of now the findings of my test found that my battery is discharging 1.2 amps on the negative terminal cable. Do you think I have to look for a electrician to find where is the culprit?
    may nabasa akong, less than 100 milliamps daw.

    you might be able to do the searching yourself, po.
    pull out each fuse, and see which one results in a massive drop in that 1.2 amp.
    then look at the owner's manual or fuse decal, to see what appliance that fuse supplies.
    Last edited by dr. d; November 21st, 2019 at 03:00 AM.

  3. Join Date
    Dec 2017
    Posts
    2,686
    #3
    Quote Originally Posted by dr. d View Post
    may nabasa akong, less than 100 milliamps daw.

    you might be able to do the searching yourself, po.
    pull out each fuse, and see which one results in a massive drop in that 1.2 amp.
    then look at the owner's manual or fuse decal, to see what appliance that fuse supplies.
    Here is a video on how to do it, although he is using a multimeter​:

    How to Find a Short in your Car - YouTube

  4. Join Date
    Oct 2012
    Posts
    27,626
    #4
    its an old car. alternator to chasis ground to battery ground to engine ground must be ok(voltage drops)

    then you can check for parasites lol

  5. Join Date
    Jan 2009
    Posts
    5,576
    #5
    Quote Originally Posted by Athrunzala View Post
    I just bought a clamp meter, and I am testing it on our 1990s Starex, is it better to use the clamp on the positive battery cable or the negative battery cable? What is the desirable milliamp range for a normal battery drain? Thank you.

    As of now the findings of my test found that my battery is discharging 1.2 amps on the negative terminal cable. Do you think I have to look for a electrician to find where is the culprit?
    Is it correct to assume that you're using an AC/DC clamp meter (not just an AC clamp meter)? Do make sure to calibrate it prior to doing the actual measurement.

    Anyway, it doesn't matter if you clamp it on the positive or negative cable. Only the polarity of the reading would change. What matters is whether or not your clamping it on all cables coming from the battery. For example, if you have accessories that taps directly from the positive terminal (ie. a subwoofer or another high-current accessory), you should include that cable in the clamp. Either that or you should measure each cable leaving the positive terminal one at a time to figure out which cable the parasitic load is connected to.

    1.2A is quite high (assuming that the tester is properly calibrated). Make certain that everything is absolutely turned off (Ignition switch to Lock, dome lights and convenience lights are off, etc.) before measuring. If you have an active subwoofer, depending on the amplifier, it may be configured in one of two ways. Ideally, it should get a signal from your head unit's remote wire to power itself on or off. But in many installations to make things simple and if the amplifier supports it, they use the auto-off feature. What this does is the amplifier turns itself on immediately once it receives audio/line signal from the head unit. Then it turns itself off when there's no audio input signal received after a certain amount of time (usually a few minutes).

  6. Join Date
    Dec 2009
    Posts
    2,994
    #6
    An electrician knows how to read diagrams..trace wirings..diagnose the problem

    If you have those skills..go ahead and try to trace the root cause

    If not..let the professionals handle it

    Sent from my SM-A520W using Tapatalk

  7. Join Date
    May 2009
    Posts
    93
    #7
    Quote Originally Posted by Athrunzala View Post
    I just bought a clamp meter, and I am testing it on our 1990s Starex, is it better to use the clamp on the positive battery cable or the negative battery cable? What is the desirable milliamp range for a normal battery drain? Thank you.

    As of now the findings of my test found that my battery is discharging 1.2 amps on the negative terminal cable. Do you think I have to look for a electrician to find where is the culprit?
    If u have an on board clock or alarm that is where your 1.2 amps is going.

  8. Join Date
    Jan 2009
    Posts
    5,576
    #8
    Quote Originally Posted by granro01 View Post
    If u have an on board clock or alarm that is where your 1.2 amps is going.
    Unless those clocks runs on vacuum tubes, they wouldn't/shouldn't draw 1.2A.

    1.2A draw from a 12V system is about 14-15W.

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How to find parasitic battery drain using Clamp Meter