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1.18 Amp draw after car goes into sleep mode

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    1.18 Amp draw after car goes into sleep mode

    Business Radio and amp are stock HK.
    Can anyone point me in the right direction?
    So I connected my multimeter to the battery and waited 16 minutes and it is showing 1.18A. I left the passenger door open and glove box open while doing this to perform the test. Someone correct me if I'm wrong, but shouldn't it be 40mA or something?
    I read the top 3 battery drain on these cars are the ihka panel with the resistor going bad, heater valve, and FSR.
    I pulled fuses 62 and 63 which i thought could be the problem but it didnt drop, 62 being water valve AC and 63 being Air conditioner. Now i guess it's not either the heater valve or the climate control panel.
    FSR has been replaced and has been working fine.
    Then I tried pulling more while I'm there, 3 instrument cluster fuses and immobilizer fuses, still no significant drop.
    Could it be a relay?
    Any advice appreciated. Thanks.
    Last edited by Halftim3; 11-28-2023, 03:26 PM.

    #2
    I suspect you have your units wrong.

    Spec is less than 40mA (0.040A). For reference mine is about 19mA or 0.019A.

    How are you measuring it? You need to make sure the car is completely asleep. But you can't run even a couple of loads like interior lights through a multimeter as it will be more than the typical 10A multimeter rating.

    Best way to do it is let car go to sleep with boot open but reset striker as if it's shut. Then put meter across negative cable and battery terminal and then break connection so current runs through the meter. You cannot allow the connection to break as it will wake the car up, draw a bunch of current via interior lights, SMG pump if you have it, Nav etc.

    Last edited by Shonky; 11-28-2023, 10:54 AM.

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      #3
      Originally posted by Halftim3 View Post
      So I connected my multimeter to the battery and waited 16 minutes and it is showing 1.18mA. I left the passenger door open and glove box open while doing this to perform the test. Someone correct me if I'm wrong, but shouldn't it be 0.040mA or something?
      If indeed it's only 1.18mA then this's the lowest draining current I have seen and nothing is wrong. I expect more than 10mA.

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        #4
        My mistake it's 1.18 Amps not mA.

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          #5
          And sorry its 40mA, edited first post.

          I am testing with trunk open, passenger door open and glove box open, interior lights off while the meter is connected in the trunk to the battery while I wait and watch the glove box light turn off in about 16 minutes. Then i get the 1.18 Amps reading.

          Comment


            #6
            Right so an amp is huge for sleep and will flatten a battery in a day or two for sure. Keep a battery charger on it so it doesn't kill your battery until you figure it out. Or disconnect the battery.

            Best you can do is similar to what you've been doing. Pull fuses until it goes away. A better method is to measure the voltage drop across the fuse. It will only be mV you're looking for but it should stand out compared to others. There are lookup tables for approx voltage drop for each fuse value (smaller value fuses will have a high voltage drop for the same current).

            The problem with pulling fuses is it may disable something supply power to the actually faulty device or unit. So voltage drop method is preferred.

            An amp is over 12W too so if by chance you had a thermal camera you may be able to find it by look for a part with a significant temperature rise but that is difficult since modules are behind panels etc. Or just by feel you should be able to tell if a module is dissipating 12W

            A relay on its own will not draw 12W. But if a relay is stuck on it could easily be supplying power to something that is drawing that much and doesn't necessarily go to sleep because it's normally controlled by the relay. Figure out the circuit first.

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              #7
              Any events prior to this current draining issue?

              I would do the easy things first: pull all glove box fuses off, one by one until the current drops. This will gives us something to focus on.

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                #8
                I just went to Electrical II a few weeks ago and I have a chart showing the mV on fuses converted to amps. I'll look for it in my folder if it's there. If not, I'll try to find the document. I've had a few draw cars since I've gotten back and it's a super awesome tool. You disable the ultrasonic sensors by pressing the lock button twice when locking. That way you don't trigger the alarm. Found this out the hard way. Pulling fuses sucks and is completely unnecessary. Sometimes it wakes the car up.
                This is my Unbuild Journal and why we need an oil thread
                https://nam3forum.com/forums/forum/m...nbuild-journal

                "Do it right once or do it twice"

                Comment


                  #9
                  Chart attached. However you don't really need it for a current draw. With the car asleep pretty much every thing should be near zero except the circuit(s) in question. Most fuses are the ATO/ATC type.
                  Attached Files

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                    #10
                    Thanks everyone who replied, I saw a significant drop to 40mA when I pulled fuse 65 which was the adjustment driver side and narrowed it down to being the lumbar switch. The switch cover has been broken and I've never really used it, but when I put that 30amp fuse back the amp draw went back up and I unplugged the switch the amp draw went back down. Btw it's my first time testing for electrical issues on this car and it's a good feeling finding the issue. Luckily I was only on the 4th fuse, but I prepared to pull/test them all and I wasn't going in order.

                    Shonky, does yours really drop to 19mA? If so, is that after 16 minutes or 40 minutes?

                    Comment


                      #11
                      Originally posted by Halftim3 View Post
                      Thanks everyone who replied, I saw a significant drop to 40mA when I pulled fuse 65 which was the adjustment driver side and narrowed it down to being the lumbar switch. The switch cover has been broken and I've never really used it, but when I put that 30amp fuse back the amp draw went back up and I unplugged the switch the amp draw went back down. Btw it's my first time testing for electrical issues on this car and it's a good feeling finding the issue. Luckily I was only on the 4th fuse, but I prepared to pull/test them all and I wasn't going in order.

                      Shonky, does yours really drop to 19mA? If so, is that after 16 minutes or 40 minutes?
                      Good you found it. At least it's not super important so you can just leave the fuse out until you sort it out.

                      Yep. definitely 19mA. Spec is <40mA so you might be close to the limit but definitely give it chance to sleep. The onyl additional load in mine is a BlueBus which I would expect to be very small when asleep. Note the Powertech (BM2 battery monitor) is directly across the battery so not included.

                      As for the time I waited, I can't be sure sorry. I just set car up, trigger boot latch (so it thinks boot was closed), lock/arm car with remote and walked away. Was probably around 20-30 minutes at a guess. I seem to remember it actually goes to sleep quite a bit quicker than they say though.

                      NB: You have to be very careful it does not wake up if running on a 400mA range DMM. It will blow the fuse instantly if anything comes on like interior light etc. Even 10A range will be an issue. I started on 10A and then by shorting out the circuit moved down to the 400mA. You cannot break the circuit at any time. As soon as you reconnect, a lot of stuff will wake up and take out the fuse.

                      from my post on m3cutters:

                      Ok because it interests me and it's good to have a point of reference if I'm ever tracking something down, I measured with a series DMM.

                      1) Put car to sleep as above with boot open and latch triggered so car thinks it's shut.
                      2) Connect DMM on current range (I started on 10A) between -ve terminal and battery clamp which is solidly connected to vehicle
                      3) Disconnect -ve cable from body

                      On the 10A range it read about 21mA. So I decided to move it to the 400mA range very carefully.

                      4) Put a shorting link across DMM terminals (so current not running through DMM)
                      5) Change DMM to mA range (probably important to do this first as internally the DMM may not provide a current path unless on the 400mA range, 10A range is usually always straight through)
                      6) Move connection from 10A to 400mA terminal
                      7) Remove shorting link

                      It sat around 18mA jumping to 19 semi frequently.

                      Only modifications to the car that might draw any extra current are a BlueBus. I expect Ted's done a pretty good job of making it low power so maybe 1mA ar so. The battery monitor you see is not being measured by the DMM.
                      Click image for larger version  Name:	image.png Views:	0 Size:	951.6 KB ID:	243993
                      Last edited by Shonky; 11-30-2023, 01:56 PM.

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