I have a really wierd problem with my car amp, plz help

Discussion in 'Digital Audio' started by J-Rod, Oct 6, 2008.

  1. macrumors newbie

    Joined:
    Oct 6, 2008
    #1
    K, I've been struggling over this for the last week or two and really need some help.

    Simply, I'm running a 10" sub off of a Sony XM-504X amp. Everything worked fine and really thumped. Jumped in one morning and started playing some music but i noticed the sub wasn't working. As random as that.

    There is an indicator light on the amp
    Green-Working fine
    Off-Cars off
    Red-The head is turned on but the amp isn't working (I think this is like a standby mode)

    I can turn my amp on (green light) and the whole setup works at really low volume, but as soon as i turn it up the amp stops working and the light turns red.

    I've checked every wire
    Tried my friends sub with it
    Good Ground

    I just can't figure out whats wrong, plz help.
     
  2. macrumors regular

    Joined:
    Jan 18, 2008
    Location:
    Faribault, MN
    #2
    Did it work with your friends sub? It sounds like an heat problem. Most amps have a fail safe for overheating. When you turn the amp up, it gets too hot and powers down.
     
  3. thread starter macrumors newbie

    Joined:
    Oct 6, 2008
    #3
    No, it didn't work with my friends sub, and no, it's starting cold
     
  4. macrumors regular

    Joined:
    Jan 18, 2008
    Location:
    Faribault, MN
    #4
    Is it stopping cold?
     
  5. thread starter macrumors newbie

    Joined:
    Oct 6, 2008
    #5
    Well, it only stops when i try and turn it up. I've run it way hot and way cold before and it didn't really effect it.

    Thanks
     
  6. macrumors regular

    Joined:
    Jan 18, 2008
    Location:
    Faribault, MN
    #6
    Where are you turning it up from? At the head unit or the amp? It could be wiring in the amp that is getting messed with if youre turning a knob on the amp.
     
  7. thread starter macrumors newbie

    Joined:
    Oct 6, 2008
    #7
    I've tried turning it up on the head, and also the gain and level on the amp. same problem.

    It's driving me crazy
     
  8. thread starter macrumors newbie

    Joined:
    Oct 6, 2008
  9. macrumors 601

    Joined:
    Aug 15, 2005
    #9
    How many watts continuous is this amp, and what gauge wire do you have running to it? Is it directly connected to the battery?

    EDIT: I should also add that you should be using preamp out from your radio leading to your amp. My guess is that your power and ground wires are either too small or don't have a good connection.
     
  10. thread starter macrumors newbie

    Joined:
    Oct 6, 2008
    #10
    0 gauge running from the battery into a distribution block, 8 gauge to amp, 8 gauge ground

    1000 watts
    850 RMS

    Usually it runs fine tho
     
  11. macrumors 601

    Joined:
    Aug 15, 2005
    #11
    Well, by Googling around, I noticed this amp has protection for temp, voltage & current faults. If temp is out, since you said it is cold, you need to check voltage and current when the volume is low and when you turn it up. My guess is voltage is dropping too low or current is getting too high.
     
  12. thread starter macrumors newbie

    Joined:
    Oct 6, 2008
    #12
    would you have any idea how to something like that
     
  13. macrumors 601

    Joined:
    Aug 15, 2005
    #13
    Yes, get a multimeter and put the meter into something just above 12V and connect the leads to the meter correctly.. Then put the positive lead of the meter on the positive feed. Put the negative feed on ground and measure. Anything around 12.0 - 12.5V or less is a problem. To note, 12 volt systems in cars are actually 13.8 volts. You don't want anything greater than a 10% difference (1.38 volts +/-). This means the voltage should read somewhere between 12.42 and 15.18, although 10% difference is getting to an extreme point.

    For current, you need to put the meter into something greater than what the amp pulls (can't find specs, but if the amp pulls approx 15A, then find something on the multimeter labeled 15A or better), and put the leads into the correct pins for measuring current. Now disconnect the positive lead from the amp. Connect the meter inline (one lead goes to the distribution block, the other goes to the amplifier), and measure the current when the volume is low and when it is high.
     
  14. thread starter macrumors newbie

    Joined:
    Oct 6, 2008
    #14
    awesome, i'll see what i can do.

    Thank you so much
     

Share This Page