I have a problem in the multimedia system in my car. Whenever I leave the car off for two days (like the weekends for example), the multimedia system drains the battery and, subsequently, I have problems in starting the car. So, every weekend I have to open the front hood, detach the multimedia system fuse and on Monday morning I attach the fuse back again. Is there another way to do this without opening/closing the hood every-time? I tried to look at the configuration of the multimedia system, but there is not totally shut off option.

Is there other solution for this problem?

  • Is it an original ICE system or an aftermarket?
    – HandyHowie
    Commented Oct 30, 2015 at 14:04
  • it is not the original.
    – M.M
    Commented Oct 30, 2015 at 14:08
  • There are usually red and yellow wires providing the permanent and switched power to the head unit. Sometimes these need to be swapped over. Quite often there are bullet connectors allowing this to be done. If you pull the head unit out, have a look if this looks possible. Sometimes a side effect of the wires being incorrect is that the radio looses it's presets when you turn the ignition off.
    – HandyHowie
    Commented Oct 30, 2015 at 14:27

2 Answers 2


If it was me, I'd wire the live supply to the multimedia system to the switched live (ie the 12V when the key is on) and not always live (direct to the battery)

That is a simple fix.

It does seem a bit strange that the current draw from the multimedia system is so high when off, though, so you may want to check the system and see if it is behaving correctly. All the systems I have had, even my current one which runs a Debian audio server, will power down to zero current draw after a time period of no activity.

  • 1
    I'm wondering if it was attached backwards in the first place. A lot of audio systems have to power feeds: one to power it (switched 12v) and the second as a "keep live" (always live). The always live one is there just to allow enough power to keep the settings and presets stored, but should be in the mA as far as draw goes. Commented Oct 30, 2015 at 11:18
  • @Rory Thanks for the answer, that sounds good. I am new to this thing, is there a way to know where exactly to wire the fuse? I do not know what is the 12V.
    – M.M
    Commented Oct 30, 2015 at 11:26

It seems very odd that your system drags so much of power . I would not recommend to directly connect to the ignition switch. Instead you can attach a relay in the following manner: (apologies in advance for poor drawing )circuit

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