My car sub amp starts to bump , and then it just turns off. but everything else stays working

Loose wire or connection is causing stereo to short out, Check all connections including amp,Stereo,Speakers and make sure nothing is touching places it shouldn't

unfortunately that's going to be a labor intensive project. You will have to follow the wires to where they go and make sure that they are all tight.

Being that the sub stays on you know you are looking for a loose wire off the other amplifier or the head unit depending on how you are powering those speakers.

if you have two amps one for the subs and one for the mains its probably not the power or ground going to them since both are not shutting down but check where the power splits to each amp.


start at the amp that isn't working unhook the cables. Test that those cables have power and proper ground then make sure they go back on cleanly (no loose strands) and tightly. proceed to follow the power wires to where they are connected.and double check everything.

If you have access to a continuity and voltage tester that will make it a bit simpler.

Depending on how clean an install it is (no panels, speaker boxes amps or seats to remove) it shouldn't take more than an hour or so. I always recommend that connections to power blocks remain easily accessible as I have had to remove amps, subs and junk like neon to get at wiring and its always a nightmare.

hope that helps

No such thing as a typical sub system. Be more specific? If the subs are moving well and just not basing you will need to check 2 things first. Try the polatity of the speakers (reverse one) they may be out of phase and will cause the bass to cancel eachother. Another cause is the box may the incorrect size for the speakers and will not give you the correct sound the speakers are capable of. If neither of those work check your amp settings and make sure its set on sub/low frequency.

your power wire is sufficating yor amp probably

check for any loose connections at the fuse block or a loose fuse
using an ohm meter would help
check the harness on the back of the radio for loose connection
bad igntion switch, again an ohm meter would help !
what type vehicle ?

your audio wires from the head unit have been pinched or discontected or the head unit is not putting out a signal

as far as it staying on it may have been wired to your hot unstead of your remote on your radio

when it runs wide open it gets hot
how are your gains

I have an alpine and I just hooked up jl 12 w3s and it kinda j did what yours did
it played.. hit hard then no subs.. my mids and highs platyed, but until I would turn off the car and restart the radio the subs immediately came on and the subs are only connected to this aplpine mrp m 650 amp

what speakers and what ohm did they wire it too?

i think my problem was I was overloading my amp feeding it a 2 ohm load or a one ohm load and it was shutting down my subs.. protectection I suppose?

Be sure to check your gain outputs on your amp it may be the case.

Are you certain you put the wires back on the amp the exact way they came off. I am not familiar with this amp but most amps if you look at the terminals where the speakers hook up there will be a plus and a minus. And generally there are four terminals. hence stereo plus and minus left and right. Some even have eight for, four channels. Since the amp is on, not getting hot and you tried two different audio inputs I would suspect speaker wiring or maybe the stuff you put in your trunk bumped a switch on the amplifier. I know this is not the exact answer you are probaly looking for but it is at least a place to start

It sounds like your amp chip has gone bad, here is some thing you can try turn on your unit then start tapping on top of with your finger not hard see if the any of the pops matches your finger taps some times when the chip starts to go out it well act like that.