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Amp cutting off while driving - battery?

7.1K views 13 replies 12 participants last post by  MythosDreamLab  
#1 ·
I've got an aftermarket HU going to a 4 channel amp split to front speakers and rears are bridged to a sub. I play the system loud as it's in a 4 season door/roofless Jeep Wrangler and it's always up against wind/road noise.

After about 6 months with this setup, the amp has been shutting off seemingly randomly.

The shutoff is instant and if I turn the car off and back on I'm good to go again. Typically it shuts off with 5-10 minutes of driving. I've found that if I turn off the sub from the HU then it won't shut off. Lower volumes seem to help too.

Im wondering if the power draw is the issue since I've been told during maintenance that my battery is on the outs and needs to be replaced. Battery is stock and nearly 6 years old. I drive the car once a week about 15 miles and sometimes it sits 3-5 weeks without turning on.

Thoughts? Things to try?

if it is battery I was thinking Red Top which I have had awesome experiences with in the past, unless there are other suggestions.
 
#3 ·
Just get a voltage meter - one of those cheap plug into the cigarette lighter socket ones will suffice - and see if there is a voltage drop when listening. Check the amp and see if it is going into protect next time as well. I think you would notice other issues if the voltage was dropping too low, such as dimming lights. Double check the power wiring and grounds too.
 
#4 · (Edited)
Modern car electronics and emissions systems can be hard on batteries while parked for extended periods. Short drives can exacerbate this and lead to the battery being in a chronically undercharged state, which tends to shorten the life of the battery.

You can try hooking up a charger and giving the battery a good long charge before your next drive and see if that makes a difference. If the amp still shuts down, the problem could still possibly be the battery, but if the battery were in that bad of shape, I think it would noticeably struggle to start the car, particularly after sitting for days or weeks on end.

Or simply go ahead and replace the battery, and see if that solves the problem. If you do, I would steer clear of Optima, as I have heard way too many folks talking about failures in recent years, from folks who used to swear by Optima, and for good reason.

All that being said, I have a feeling it is something wrong with the amp or wiring. :)
 
#5 ·
I also agree with faulty amp and or wiring. 4ch amp will not draw enough power to give your battery issues unless that battery is dead-dead. If it was dead-dead it probly wouldn't start your jeep.

6 years is a long time Though. I'd replace it with a quality AGM, and see if your still having issues.
 
#6 · (Edited)
While I agree that replacing and upgrading (to higher amperage) your battery would be a good thing, the fact that the amp cuts of after a few minutes, along with you saying it is less so at lower volumes, sounds like the amp is overheating and triggering its shut-down circuitry.

So, if it continues after you get a new battery, go ahead and get a new amp too...

I replaced my battery recently with the Gel-type (instead of the watery battery acid), and have had no issues...

What brand Amp is it?
 
#7 ·
3rd the sentiment of not being the battery causing your issues. Now, if the amp is cutting out only when you come to a stop, it could be an alternator that's about ready to go out, but still charging enough at higher rpm to keep the battery going and starting your jeep, but you'd notice that with headlights dimming really bad at stoplights and off throttle/ at idle. Still, you'd probably notice the battery is a bit weak when starting, the slower cranking would be noticeable.

I'd check the grounds at the battery/frame/body and at the amp first. Pull them off and clean 'em up with sandpaper/file and put some dielectric grease on the holes, or at the very least, some regular grease if you don't have dielectric grease. See if that clears up the problem.

Clean up the battery terminals too, if they're corroded and all nasty, that could be causing a drop in voltage. Replace the battery with a good AGM battery if you really want to upgrade it, and change out the terminals too when you do it so you don't have to deal with all the corrosion that's more than likely there right now. This will also give you a good, solid connection to the vehicle and to all your accessories that's connected to the terminals.

I'd suggest going with an Odyssey battery if you're gonna spend money on an AGM battery. If that's too much, try out a Deka Intimidator AGM battery, my son has that in his 4Runner, 4 years old now and its just like new!

For me, I have Odyssey batteries in 3 vehicles right now, oldest being about 8 years old and no issues starting that '11 4runner. Of course, I am anal about my batteries and use a conditioner charger (Odyssey 20A charger or a Noco 5A conditioner charger) every 3-5 months for about 24 hours or so. Keeps them all topped up and happy!!!
 
#8 ·
Go to costco and get the proper agm battery for the car. Winter is coming so u will need one anyway. Without knowing what equipment you have its hard to make recommendations.
read about the big 3 upgrade as well
 
#9 · (Edited)
Does it do the same thing if stationary with the motor running, with the system playing at the same volume as when driving? (If not, this may point to a vibration related problem, e.g., an intermittently shorting speaker wire, a loose or corroded power or ground cable, or a cold solder joint or other internal amp or head unit problem.)

Next, I'd suggest measure voltage across the +12V and ground wires, (at the amp), while playing the system at your driving volume. (Low voltage here, particularly on loud passages, suggests inadequate power or ground.)

Try those for now and report back, please.
 
#10 ·
I had an aftermarket hu that caused a parasitic drain. Screwed the battery. Without knowing what equipment you have we can only give you generic advise.
 
#12 ·
at what impedance you have your subs connected to the amp - problem might be too low impedance, amp overheating or even motorboating.

find somebody that can measure your battery, clean all the connections on battery, distro block and amps. I would also change all fuses on distro block and on the amp
 
#14 ·
Ok, we can probably slow down with the help.

OP has not been back to the website, since he posted his question FIVE days ago (and counting)...

Maybe it's solved(?)