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The car amplifier doesn't provide a signal to the sub

I have the most perplexing of issues at hand, and I don't know where else to turn to but here.

My sister's car -- namely, the car's sub amplifier -- is giving me all sorts of sass. I'm trying to diagnose it from a world away (she's in Tennessee, I'm in California) and it just does not want to work properly.

A bit of background: I sent her my old subwoofer and amplifier because her setup stopped working awhile back, and she was unable to take her old sub+amp up to Tennessee when she moved anyway. So, I shipped her my sub+amp in "known good" condition, and my amp just flat-out refused to work. It powered on briefly (the yellow LED on the amp itself turned on, but not the green LED on the subwoofer level controller), but turned off as soon as she hooked up to sub... And then it never powered back on again.

So after some brief multi-metering, we chalk it up to a bad amp and she orders this Boss amp from Amazon.

Yesterday the amp arrived, and we're back to square one. These are her installation pictures: pic #1 and pic #2. Please refer to them, as I will be using the specific names found on the amp. This is what I know, according to sister:

  • The green Power LED is lit, and the Protection light is *not* lit.
  • Batt+ and Ground have 12.8ish volts across them when measured with a multimeter.
  • Remote and Ground have some negligible voltage across them when measured with a multimeter (and the radio is on) -- but that voltage goes away when the radio is turned off. So I'm assuming that the amp gets a signal from the radio to turn on.
  • Speaker Connections have 0 voltage across them.
  • I had her test the continuity of the sub by measuring across the subwoofer terminals. Since the multimeter doesn't have a "continuity test" mode, I had her do the old-school Ohm method -- setting the meter to 200 Ohms. With multimeter leads not touching, the multimeter reads 1 Ohm. With leads touching, it changes to 0.1. So touching something that has continuity should change it to 0.1. She tried this on the 30 amp fuse on her old amp, and the method worked (the multimeter changed to 0.1). However, when she puts the leads on the subwoofer terminals, no change happens. But if she connects the speaker cables from the amp to the sub and performs the same test, the multimeter reads 0.1.

So that's where we're at. I basically have three questions:

  1. Should the Speaker Connections read 0V across them? I thought that there should be some voltage coming out of those terminals that would indicate that sound was being output.
  2. Piggy-backing on the previous question, I'm curious if there would be any voltage coming out of the Speaker Connections if the RCA audio jacks were bad (basically the audio signal coming from the radio). So a) would there still be a voltage coming through Speaker Connections, and b) does anyone know of a good way to test if an audio signal is coming from the radio through the RCA jacks? I would have her do the Ohm method for continuity, except the opposite ends of the jacks are like 15 feet away, one side being by the radio, the other in the hatchback area.
  3. Should the multimeter Ohm reading change when she measures the subwoofer terminals? As far as I recall, the sub is wired in parallel internally (it's a dual coil Rockford Fosgate Punch HE2), but I assume that it should still read some resistance value that is not 1. I figure that even if the sub had tons of resistance, the multimeter reading should spike to some other value, since the multimeter was put on the lowest possible Ohm setting.

The issue is that the sub is encased in a completely sealed enclosure, and she'd have to tear the whole thing apart in order to ensure the wiring is fine. So I'd love to be able to *not* have her do that if at all possible.

Thanks in advance!

Answered! View the answer I have this problem too

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Where is your ground point

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My bass from my boxes keep going out! But the amp doesn't go in protection mode!! What's wrong!! Radio still play! And amp comes on but the bass won't come back on. Why?????

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I hooked up a amp and subs and when I play my radio the amp and subs work but when I put in a cd the amp and subs cut out and then I turn the radio back on and my amp subs cut back on what's my problem.

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Remote wire is to power antenna then. You need to run the remote to the remote wire hookup behind head unit or if you have factory hook it to 12v. Constant in the fuse box

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Chosen Solution

My sister was resourceful and instead of taking out the sub, she instead took off the side RCA jack panel so she could check the wiring.

Lo and behold, one of the wires that connect to the RCA jacks had come loose on the inside. She secured it properly and everything worked fine afterwards -- including the old amp!

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I have a problem with my 2200.1 watt amp.. the led light won't go green it just stays read... I connected everything the right way but then yet it don't get any signal

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She has the remote wire crossed with the power antenna wire in back of her stereo.

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I have two sub speakers and for some reason they are brand new and the amp is plugged in just right and speakers are good and ground battery and I have the blue ignition to the back of the amp and we tried it doesn't work ??? Then we thought it was stereo took it out got my friends nope not problem then we thought the amp so we tried putting his in doesn't work then we tookmy amp and put it in back of my friends truck it works anyone plz help me I'm lost and do not know what's going on we replaced all the fusses and everything good

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I have everything hooked up to my amp and everything thing is right lights are on and it all working right except for my subs they will not play I hooked them To my door speakers and they work but they won't work on my amp

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Most Helpful Answer

Im having the same exact problem my amp i just got off amazon is a boss audio 5000w and it is turning on fine as well with my deck but the only thing playing the music is the regular speakers so i went threw everything and the only thing ive come up with is that the RCA outputs are not reading 12v like they should and yes my car was running when i tested this and i would have to take this deck completely apart to see the connections behind and dont know if i would even be able to put it back together, so should i assume that is what is wrong ? The decks red and white RCA plugins are shot , and get i new deck and sell this one because it works for everything but getting the music back to the amp witch someone wanting just a deck wouldnt need ? Im probably going to pull it apart and look at the connection ill post back to see if i got the solution.

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Sometimes the blue wire is for power antenna and only comes on when the tuner is selected. So double check if there is another blue wire coming out the back of the deck and if so use that wire instead.

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When the accessory power is on or the car is running, the Remote to Ground connection should measure 12V.

If there's a negligible voltage coming from the source of the remote wire, that's probably the issue - especially if the problem persists with different amps including a brand new one.

Have your sister check the connection of the remote power cable.

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of course check all grounding points. then try bypassing the remote power cable.

stupid question but does her radio support a sub amp or are you just running speaker signal to the sub assembly?

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Have you tried remotely testing it? As in using a different power source? Just seems like a hiccup if you're not getting any power. Maybe even a sensitive amp. I know my kenwood deck would give me errors all the time when I tried to install it. Wether I'm wrong or right about how I fixed it, I THINK there wasn't enough continuity within the speaker wire. I cut the the wires shorter and had less wire available, worked after that.

I use to hook up amps and subs for testing with various speakers and such. I say start with the power source though.

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check all of the grounds to the amp and to the radio. bad grounds could be the issue because the radio pulls more of a load with any amps or anything else connected to it. also disconnect the remote? does that work. try taking out your input lines one at a time see what happens. try taking one of the input connectors and switch left to right. any changes. write back with what happens

nick

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Hello My name is Heather.I'm sorry for what your sister is having trouble with her sub's powering on,but nada is coming from the subwoofer's.well I use to have six ten's in my little Saturn about two years ago and one day pulling out of a store my music just stopped playing out of my speaker's so as me and my best friend was troubleshooting what the !@#$ happend we noticed that all that music my radio couldn't handle and their for my rca's plugs on the radio was blew out the frame..so yes your second guess that you mentioned about it being bad rca jacks on the radio.I would have her go with that being her issue cause it was so mine and I had to replace my very $$costly tv/radio with another and !@#$ it if it did start to play music threw my sub's again.so good luck to her.I know how she is feeling cause I once was there too.

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Hey Miroslav, you are having lots of knowledge about the music system. Even I don’t know so much. Thanks for sharing all the stuffs that you tried to fix the amplifier, I must say, it is not a big deal to fix the amplifier but sometimes it is better to let the mechanics to deal with such issues. I prefer Porsche repair Dallas for all my car issues. I would like to suggest you to go for the repair center rather making random efforts, also learn from the mechanic what really needs to do to fix it. That would be better to have a clear idea so that you can fix it by your own in future. Thanks.

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Miroslav my friend, I think you have almost done everything that you could. I'm pretty surprised that you have lots of knowledge regarding auto parts and how to diagnose them. Problems with amplifier is a minor one but finding the fault goes this much tough. You can take the help of auto care centers, you may have a visit there or simply you can get the assistance over phone. German Auto repair Safety Harbor, FL . Even I'm a car person but I don't have much knowledge on it. Hope it'll helpful to you.

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Miroslav Djuric will be eternally grateful.
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