New battery and alternator..discharging.

Discussion in 'General Electronics Chat' started by capricon250, Mar 28, 2007.

  1. capricon250

    Thread Starter New Member

    Mar 28, 2007
    My friend has this problem where he has to disconnect the battery leads everytime he parks. Are there any electrical areas that are most likely to cause this that he could check? Any advice appreciated. Thanks
  2. Gadget

    Distinguished Member

    Jan 10, 2006
    Crook or miswired stereo or radio
    Courteousy light staying on.. (nb check the boot, as a crook switch or slight ding in the rear end may cause the boot light to stay on)
    Crook security alarm
    Crook engine management/computer etc etc etc

    Really, you will have to measure the current draw and trace it back... possibly by pulling out each fuse 1 by 1 and inserting an ammeter to isolate the problem circuit.
  3. wireaddict

    Senior Member

    Nov 1, 2006
    Yup, & a vehicle schematic would be valuable, too; if you find current flowing in a wire [or voltage on it] the drawing will show where the wire goes & possibly where it could be picking up power from.

    An alternative to checking for current flow is to ground the neg. side of a DC voltmeter & use a hat pin or diaper pin to poke a small hole in the insulation on wires to see if they have voltage on them [connect the pos. meter lead to the pin]. Tape the wires up after checking them this way.

    If you need to work under the dash, the smaller you are the better. Good luck.
  4. TFSI

    New Member

    Mar 30, 2007
    You need to check the closed-circuit current drain.Deepending on the type of car and number of available control modules, you will have so much drain, eg.0.40mA as standard.But your fault may be heavy drain type, it could be radio which does not switch off or any retroffited aux.player in the car.But u need to do the drain test to find out.Goodluck