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1.9tdi passat drains battery too fast

JorKSX Nov 21, 2017

  1. JorKSX

    JorKSX New Member

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    So im having little problem with my passat, 1.9tdi engine 85kw and year 2000, variant.

    When car is running the voltages are like 14.5 so the alternator is good.
    Also battery is good for sure. (car is build for subwoofers and there is 3 extra big batteries but they cut off when I shutdown the engine)

    So basically when engine is not running there is only one battery connected and its under the hood. I have changed the battery and tried with many diffrent batteries but all of them drain too fast.

    To the problem:
    I connected my amp meter between battery - and the black wire. And I see 0.8A draw all the time. It was 1.4A but dropped to 0.8, also sometimes its 0.4A and its still too much. Something like 0.04A is normal I have read.
    (im electrical engineer just to point out so I know what to mesure and stuff)
    And yes I tested these mesurments after I locked the door and waited 1h that CCM could go to sleep.

    Then I removed ALL fuses and relays that I could find. Draw was still 0.4A
    Okey I put all fuses back and started removing power wires from driver side where relays are. After I removed few wires and did mesurments again I saw 0.2A peak and after few secconds it dropped to 0.04A and at this point I was happy.

    Tried the things that did not work. Trunk lock works, door locks wont work and power winodows wont work.

    Okey I attached all wires again and removed fuses #14 and #37 witch are main power sources for CCM(?) and the draw stopped. So the problem is somewhere between CCM and power windows and locks.
    I put fuses back and removed every bulb inside the car and also removed all doors connectors.

    there was still too much current draw,
    Yes Between every connection that I removed or fuses I pulled and put back I waited because some things wake up when I attach the fuse.

    all fuses attached I started to look again the power wires. Found blue connector from driver side footwell left side, If I cut the power wire there, the current draw stops. and power locks and power windows wont work.

    thers no can-bus in that connector just to point out :D
    There is no fault codes for power window or power locks. Did vcds read.

    problem is not IN doors because I disconnected every door and there was draw.
    Is the CCM really bad? checked the CCM and all seems fine there, no bad wires or no water anywhere.

    Every wire back and all fuses back the power locks work fine and also power windows work fine, no problems.
    So what do I do next? Anybody there that knows passat electronics or has full wiring diagram of ccm? :D

    edit//

    When car is running voltages are 14.5
    When I turn off car and remove battery connections and wait 2h, the battery voltage is 12.8
    When I attach the battery to the car again and wait 2h, the car has 11V and wont start.
    Also I have removed every single connection almost in the car, blower motor, dashboard and every single aftermarket stuff, problem is not in these things.
     
    Last edited: Nov 21, 2017

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