Sub power variation? Need Help.

neomac3444

Junior Member
Hey guys,

I'm new to the forum and need some help. I have searched many places for my problem either no one has had it before or I'm searching the wrong things. Anyways while driving or stopped at a light my sub will be at full power then decrease to less than half and come back almost continuously. Occasionally it will shut off completely then come back on and keep doing it. Its been doing it for 2 days now. I have already torn my box apart to make sure no loose wires I checked at the head unit, amp, and sub.

I have a feeling it is either my head unit or my amp. Is there a way to test one or even both of these as the problem?

Also this system went into my truck in Nov 07 with no problems till now.

My system:

Sony CDX-GT320 Head Unit

Pioneer GM-5300T Amp

Kicker 08 CompVR Sub

If you guys have any more questions feel free to ask.

Thanks ahead of time.

 
I think your electrical is telling you to chill the **** out... When idling your alternator doesn't do much so your battery is being drained giving you bad voltage drops.. Do the Big 3 and go from there..

 
First, I know it isn't that since while on the highway with my engine at 3000rpm it still does it and at that point the system is almost on all alternator. Second the battery is new as of beginning of last winter (and i always buy the biggest one I can) and i got a 150amp alternator (2 years ago) with a digital readout of volts in my truck. Even at idle with all my lights on and my stereo as loud as I want to push it I never see the Volts drop below 13.2 (Normal volts 14.28) and this is happening at low volume also not just peak volume.

 
Did you check all the power/ground wires for your amp and headunit? You live in the Northeast which has hard winters, maybe a ground coulda got rotten and is robbing your system of a good connection with rust.

 
well i know its not a bad ground for either. Especially for my amp since its under my seat belt bolt. If that was rotted I would prolly notice quickly. I just cleaned off my battery terminals and still have the same problem. //content.invisioncic.com/y282845/emoticons/pissed.gif.9f665f96bc89e98e708dabd4580bb591.gif

 
seat belts are awful ground points. i don't like using them for a reduction in safety and increased resistance.

monitor your battery voltage when the amp does this. if you don't know the voltage at the battery and at the amp, you don't really know what's going on. when you monitor amp voltage, monitor the amp terminals. this may be tricky while you're driving, but it should do the same thing when you're just idling in your driveway.

go to an autoparts store and have your battery and alt load tested. both of them can fail.

most likely, it's a low voltage problem. below 11V the amp will shut off. below 12V the amp will lose power.

 
So here's my update. Its still doing it. Battery tested and came back as good. Alternator tested and came back as good. Amp light will remain on when sub stops hitting or looses power. Another suggestions?

 
ok your amp light is just letting you know it has some type of power dose your amp have a protect light sounds like its protecting it self clearly

also you may have damaged the amp between installs if you did not disconnect and or re connect the amplifier correctly it is very possible that you shorted it

try a new amp and come back and thaank me haha llol jk

but yea giv a new amp a try a

 
Well first its only been installed once from brand new. Second and not to sound like an jerk but i am quite knowledgeable with electronics. I know I did not short out the amp during install.

What I would like to know is can I test the amp of input signal from the head unit?

 
like i said sounds like the amp is shorted ...just test it with a new amp

unless you like dropped the sub and messed it up

it is easy to short a amp install/uninstall (may come on and all yet the sound can be trashed )

 
So the sub has never been dropped and has yet to leave its box except for 4 days ago when i checked to make sure no wires were loose in its 2.5 years in my truck.

Amp has never left my truck since install not even unplugged therefore i would have noticed crappy sound quality if it was shorted when it was installed.

And I dont just have an extra amp laying around to test it on. It means i have to go buy one or have a friend rip it out of his car and let me borrow it for testing purposes.

 
ok i thought it was uninstalled and reinstalled ...

ok check and redo all fuses to start even in the deck

and where are your main power leads connected?

 
Checked this morning Fuses = good

The power leads go from my battery terminals through a fuse to my amp. Also, since I just took my battery out of my truck I did clean the terminals and wires that attach to them to ensure a good connection.

The power for my radio is just off the stock harness adapter.

I convinced my friend to let me put my amp in his truck to test it so I will let you know what happens with that one.

 
Well the amp was in my buddies truck for 3 days and he said that it never quit on him once for the time it was in there.

So it would either be the head unit or the sub. I doubt that it is the sub since the amp is under powered for the sub so i cant blow it. And it still hits hard.

 
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neomac3444

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