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MTX Amp issues -- Battery issue?

Discussion in 'The Garage' started by tch777, Feb 18, 2005.

  1. tch777

    tch777 1/2 ton status

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    Well we jumped in the Sub today at lunch to go shopping. No start no clicky dead as a door nail. I had used it the night before to run to the store too.
    So it sat for 12 hours and the battery was dead. Can't find anything we left on by accident. So I put the charger on it to see if she will charge up. Then I notice that the power light on my MTX 504 Blue Thunder is glowing faint red without the stereo on. Hum check the fuses, all good including the one I added to the power side of the amp near the battery. Power light did go out with fuses removed. I checked for loose wires and everything all secure. I then checked voltage, 12.66 Volts at the battery and 8 volts at the AMP for the AMP power and the remote turn on wire. Is this right??

    What do you think could be wrong? Amp, battery or???

    Thanks

    Tim
     
  2. 84_Chevy_K10

    84_Chevy_K10 Banned

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    8 volts at the amp?

    What size wire are you running?
     
  3. spearchucker

    spearchucker 1/2 ton status

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    Are you sure the alt. is good? You should be getting about 14.5V when the alt. is excited.
    You could always check for a power drain while the truck is off. Just disconnect one terminal on the battery (either one) and hook an ammeter in between the cable and battery. There shouldn't be any reading on the meter unless you have a computer controlled truck, in which case there should be about 100 milliamps. If you find a power drain then you need to start pulling fuses until the reading on the meter drops. Then you get to back track from there. Fun stuff. :whistle:
     
  4. Spkrman

    Spkrman Registered Member

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    sounds like it could possibly be an issue with the remote wire.

    pull the remote wire and see if the amp turns completely off.
     
  5. tch777

    tch777 1/2 ton status

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    8 guage


    And thanks for the ideas I will try those.

    With the engine running I am getting 14.6 volts at the battery.
    And 10 volts at the amp.
    Remote wire is still only 8.6 volts with engine running.

    Thanks

    Tim
     
  6. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Anything running off the vehicles electrical system should be within a few tenths of a volt of what you're measuring at the battery..... if it's 12V, the remote turn on lead should also be 12V.

    Sounds like a bad wire, or something that's creating a voltage drop. I'd run a "bypass" wire (just something temporary) from the battery to that amp and see if the behavior changes. If it's a bad wire the voltage will come up to normal....
     
  7. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I'd be more concerned about a bad ground than anything else.
     
  8. Spkrman

    Spkrman Registered Member

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    yea... with a FOUR volt drop from front to rear... *something* is wrong.

    It can be either a bad ground, a semi short on the + run, and the remote wire should be 12 volts, not 8.

    You need to upgrade wires all around, that amp needs 4ga anyway, and up your remote if you are using a particularly puny one... no more than 16 guage wire will get the job done, 12 is nice, but a lil much. Some cheapy kits will come with 20-22ga wire, which just sucks.

    You have alot of issues that need to be addressed either way, take care of that and see where it leads you :)
     

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