Car Audio, Video, & GPS

Car Audio, Video, & GPS
Talk about stereos, navigation, amps, subs, and all things car audio


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I am running a pioneer GM-D8061 amplifier and for some reason it stopped putting out to my sub. I had my setup running great for about a month and then it took a crap on me. At first i thought it was the amp so i used my warranty and got a new one. After I got the new one I put it in and still nothing. I used an RCA to 3.5 mm cord to test it and still nothing. Also I met up with my friend who also has a sub set up and i tested my sub with his amp so i know my sub works. Now I think the issue is with the power supply. When my car is turned off and the amp is off the power cable reads 12v. But then when i turn on the amp it drops to around 8v. But even with this happening The blue light still comes on. So is the voltage drop causing my problem?? If that's not it what else could it possibly be???

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  • Yeah, the amplifier won't actually power up with less than 10V or so. The LED power light however doesn't require any real power, so it can illuminate when voltage in quite low and in fact, some amps only need a signal on the turn-on lead along with the amplifier being grounded in some way for the LED to power on, indicating the amp is on, when in fact it's not. It can even be as little as RCA cables and the remote lead being the only things wired to the amplifier for that light to power up.

    Anyways, now that I've gotten how useless power lights can be on amplifiers, lets see what we have here.

    You say the power wire at the amp drops from 12V to around 8V once you try to power on your system? Is this with the car running?

    What's the voltage at the battery when the car is running? How old is the battery? Any loose connections at the battery, fuse holder, or amp? Have you tried replacing the inline fuse?

    I would like to believe that if the voltage dropped to around 8V at the battery, the car's engine would die as well.

    What is the vehicle?

  • u didn't mention if you checked the primary fuse for the amplifier power cable, that would cause your issues if it blew.

  • Not that it helps, but not all vehicle engines will shutdown when battery voltage is low.

    GLH Geeked

  • Yes that drop occurs when the car is running. It is a 2014 ford focus so it is fairly new battery and there is no voltage drop at the battery or coming in or out of the fuse. What do you mean replace the inline fuse?

  • Yes that drop occurs when the car is running. It is a 2014 ford focus so it is fairly new battery and there is no voltage drop at the battery or coming in or out of the fuse. What do you mean replace the inline fuse? and also i checked and there are no loose connections at the fuse

  • Hmm, this is becoming more puzzling.

    What I meant by replace the inline fuse, is just that, replace it with a new one. It's rare, but there have been instances I've seen where replacing what seems to be a perfectly fine fuse seems to fix the issue. Fuses are fairly cheap and easy to replace. However, you say there is no voltage drop on the directly after the inline fuse.

    Still, you get voltage drop at the amp. So, the issue must be somewhere between the inline fuse and the amp.

    What brand and size is your power wire? What amperage is the inline fuse? Who ran the power wire to the amplifier?

    I'm wondering is the wire may be damaged.

    And just out of curiosity, where is the ground attached to the car at and was this location free of paint/residue?

  • KIT2 8 Gauge Amplifier Installation Kit with High Performance RCA Interconnect and Speaker Wire. I bought that kit from amazon so it is an 8 gauge wire. i installed the power wire myself. I used the fuse that came with that kit and it is a 50 amp fuse. And the ground is attached to a bolt in the rear of the car and yes i took of the paint before connecting it. Even so would I know a  bad ground can cause issues but would it cause a voltage drop?

  • Well, that amp kit sure isn't helping matters, to say the least. My searching indicates it's a Boss Audio amp kit and in such, it's not of high quality. It's likely smaller than true 8GA and/or CCA instead of pure copper. Either way, it comes with a 50AMP fuse, when quality, true 8 GA can support and come with 60AMP fuses.

    Your amplifier has 80AMPS of fusing and it's recommended one uses 4GA. No idea what load you are presenting to it, 2 ohm/4 ohm, but obviously the amplifier hasn't drawn more than 50AMPS, or else the inline fuse would have likely blown.  

    A poor ground can result in voltage drop. Were you using the ground for the amplifier when measuring the voltage on the 12V wire? Even so, it doesn't seem like a poor ground is your primary issue, but it could be a factor.

    Hopefully the bolt you used provided a secure connection to the body of the car and you were able to remove the paint/primer from the body of the car. Not saying it's so, but I've seen many factory bolt locations be used by people and it being a large part of their problem.