1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Clarion audio ACC 12V drops to 3V under load

Discussion in 'Automotive Electronics' started by Oziam, Jan 7, 2016.

  1. Oziam

    Oziam New Member

    Joined:
    Sep 18, 2014
    Messages:
    13
    Likes:
    0
    Hi All,

    I have a Clarion car stereo (model#BP9K 66 ARX) and have added an after market media player module to the sat nav plug as shown below in legend J702.
    All works well with the exception of pin(a) ACC 12V, using a multi meter it shows +12V as expected but once ANY load is drawn it reverts to +3V, I have tried different methods including a voltage regulator, diodes etc... with no success. If I connect to pin(i)B/U 12V const. it works fine but then the media player is on all the time so at the moment I have tapped into J701 plug, pin(v)ACC & all works great but I would like to have it working from ACC using J702 only. Any help would be much appreciated. TY

    [​IMG]
     

    Attached Files:

  2. cowboybob

    cowboybob Well-Known Member Most Helpful Member

    Joined:
    Oct 22, 2011
    Messages:
    3,051
    Likes:
    479
    Location:
    James Island, SC
    Knowing nothing more than what you've shown and described, I suspect that 702 is an output connector (judging from the other signal at the other pins) with a limited current capability, especially on pin 1 since it's just a control voltage signal, not a power source. Thus the drop in voltage with the load you're applying.

    Pin V on 701 (ACC) is the Vcc power in connector, which is why it works as it should.

    Could be wrong, of course, but it makes sense to me...
     
    • Agree Agree x 1
  3. Oziam

    Oziam New Member

    Joined:
    Sep 18, 2014
    Messages:
    13
    Likes:
    0
    thanks for your input cowboybob, definitely sounds feasible, if I find out more I will post it here.
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

    Joined:
    Oct 30, 2010
    Messages:
    9,968
    Likes:
    1,099

    I agree with cbb ACC is essentially coming from the ACC of the ignition switch or what on after start and in the accessory position.

    aux-cont is likely a low current 12 V out used to do things like turn on an amplifier and it's likely connected to amp-cont.
     
    • Agree Agree x 1
  6. Oziam

    Oziam New Member

    Joined:
    Sep 18, 2014
    Messages:
    13
    Likes:
    0
    what is confusing is J702 pin(a) is labelled ACC same as J701 pin(v) not AUX-CONT, aux-cont goes to ground to tell the head unit there is an auxiliary device connected & to make aux mode selectable.
     
  7. cowboybob

    cowboybob Well-Known Member Most Helpful Member

    Joined:
    Oct 22, 2011
    Messages:
    3,051
    Likes:
    479
    Location:
    James Island, SC
    Probably labeled ACC to indicate the source of the electrical condition (On or OFF, High or Low) as a low current voltage trigger or state (not unlike AUX-CONT, just a reversed polarity).
     

Share This Page