Amp/subs draining battery

[NCjeepgirl83]

I have an older Rockford Fosgate Punch series amp and two 12" subs in my XJ. I had them installed professionally at Freeman's car stereo in Charlotte. They ran a wire from the amp to the battery. However, ever since then, when the XJ isn't driven for a week or two, I come back to find a dead battery.

The subs are hardwired to the battery, and it had gotten so bad that I'd have to get a new battery every 6 months, which seemed ridiculous. In an attempt to solve that problem, I opted for an Optima yellow top battery last June. However, after the XJ sat for 2 weeks, it's not starting. I got it to turn over, but that was only by giving it gas. As soon as I took my foot off the pedal, the engine would die.

My question is for all those who have high-end or high-tech subs/stereos/speakers in their XJs: how do you wire it so that it doesn't kill your battery?

I don't drive the XJ very far each day (<10 miles) and it only sees city driving (no long highway trips). Right now it's at the dealer, who informed me that I have 2 options: they can wire it to the ignition so that it turns off when the car is off, and no power is going to the battery, or they can install a kill switch that I'd have to turn off and on every time I got out of or into the car.

I worry that the first option would be it would put too much strain on the ignition or give it the amp too much power or something.

What would you suggest? Urban_yan, in particular. Do you have kill switches or some way to prevent the amp from draining your battery?

Thanks all in advance! I wanted to get some input here before I decided what to do.

Edited to add: I had one guy look at it from Tweeter (another audio-video specialist) and he said the amp is on the low end power-wise, if that's any help.

 

[hubs97xj]

Most amps have a lead that connects to the deck. When the deck is turned on, it switches the amp on, and when you turn the deck off, it kills power to the amp (it's just a built in relay in the amp, I believe). Even my old Pioneer and Sony amps (about 10 years old, I would guess) had this setup. I'd be fairly surprised if your amp doesn't have this feature- I'd thought it was standard on all amps.

 

[NCjeepgirl83]

Most amps have a lead that connects to the deck. When the deck is turned on, it switches the amp on, and when you turn the deck off, it kills power to the amp (it's just a built in relay in the amp, I believe). Even my old Pioneer and Sony amps (about 10 years old, I would guess) had this setup. I'd be fairly surprised if your amp doesn't have this feature- I'd thought it was standard on all amps.

Hmmm maybe that's the problem--I hardly ever turn the CD player/head unit off when I turn the Jeep off.

 

[hubs97xj]

Wait, does the head unit still have power when you turn off your Jeep? If it does, that's likely your problem. If it turns off when you turn the key off, that shouldn't be it.

 

[XJCruiser]

Rockford amps definitely have the "remote" lead that you are talking about hubs. I used to work at a parts/accessory store that is an authorized Rockford dealer and have installed many many subs and amp combos.

NCjeepgirl you shouldn't have to turn the head unit off every time you shut the ignition off. Apparently the professional installer doesn't know as much as they think they do. First off you should have a Main POWER Wire running from the battery down the left side of the vehicle into a fuse of some sort then to the amp. Then the "remote" lead that hubs was describing will get spliced right into the wiring harness for the head unit and ran to the amp. There should be a specific wire just for remote turn on (blue or blue/white in some cases). And of course a ground wire sufficient enough to handle the wattage for the amp to the chassis, along with your "RCA" hook-ups. Your wiring should be Power/Ground on Drivers side, and "remote"/"RCA" down the passenger side. I can suggest a few things to help correct the problem.
1. Replace the negative ground from the battery to the chassis (good place to start)
2. Have a capacitor installed to help lessen the drain on your battery/alternator
3. Find someone who knows what they are doing re-install and teach you how along the way (it is an extremely straight-forward procedure)

Hope this helps

 

[NCjeepgirl83]

Wait, does the head unit still have power when you turn off your Jeep? If it does, that's likely your problem. If it turns off when you turn the key off, that shouldn't be it.

No, the head unit turns off when I turn the key off. The only power it has is to eject or insert a CD, but no lights come on or anything.

 

[gradon]

As said, there should be a remote wire from the head unit that turns on the amp when the unit is turned on, not wired to the battery to be continuously on. I swear by those RF amps from the early-mid 90s and am using a 400x4 to power my current system.

 

[hubs97xj]

Wouldn't the amp need that remote wire connected in order to operate? If that's the case, maybe someone wired hers to something other than the HU's remote lead? Say, the memory lead, or any constant power source instead of a switched lead? edit- duh, I guess that's what Gradon said already.

When I first read the OP, I assumed she meant the power wire for the amp, but maybe the mechanic is referring to the remote lead? That would be a really shoddy install if they ran the remote and the main power directly to the battery.

 

[HMGanja]

I will chime in on the older RF amps. I have a older RF Punch 3001 in my XJ powering two 12''s and have never had a problem. Just to clarify: You should have RCA's runing from the head unit to the amp; you should have a power wire running from + terminal on batt. to + on amp; you should have the - wire running from amp to proper ground; then, you should have a "remote" wire running from head unit to amp (although in my case I have the stock head unit and ran it to 12v switched in fuse box). With this you should have no problem with wiring itself. Unless whoever installed the head unit wired it into a constant 12V source.

 

[urban yan]

It's amazing how our driving patterns/ problems parallel. I also had the exact same battery issues a while back. They weren't stereo related but they plagued me for years. I was boosting my truck every 2 weeks (if not more often) and replacing my battery every 6 months (even red tops). Nobody knew what was happening. I went through several mechanics without luck, and the dealership was the biggest waste of my time/money. My truck died less than 2 weeks later.. when I called to complain they told me it wasn't their fault because they weren't trained to deal with aftermarket issues.

I even had a remote kill switch installed, but it was such a royal pain. First you had to use the factory fob to lock the jeep, than the kill fob to disconnect the battery, you had to open the doors manually (truck had no juice afterall), and you had to connect battery with the hidden switch before you could start the truck. A manual kill switch is no better IMO. Let's not forget you lose your head unit's settings everytime you use the kill switch.

In my case, It turned out the previous owner had a vehicle tracing system installed behind the headunit. It had it's own, failing battery pack that was charging off my main battery when the jeep sat. It's hard to believe something so insignificant could cause that much drama, so I can honestly say I feel for ya. Mysterious battery drains = FAIL.


If I were in your shoes, I would go back to the same audio shop to complain they messed up my Jeep; a reputable shop would stand by their work. Otherwise, I would find a better audio shop to fix the problem. I'm not sure I would recommend the dealership to troubleshoot aftermarket problems. Personally, I have a go-to guy for all my electrical installs (stereo, hids, etc...). He's got nearly 30 years experience; he's the only one I trust to do a half-decent job. If you find someone that does good work in your town than be sure to keep their number.

 

[wolfpackjeeper]

most decks have two remote wires. If you use the wrong one this happens. One is blue, the other is blue/white I think. At least on my Pioneer Decks. The both operate the amp, but one is meant for a different setup.

 

[XJCruiser]

most decks have two remote wires. If you use the wrong one this happens. One is blue, the other is blue/white I think. At least on my Pioneer Decks. The both operate the amp, but one is meant for a different setup.

yes you are right one is an "amp/pre-out" turn on and the other is for a power antenna "turn on" i just couldn't remember which one is which when i posted earlier

 

[skinner]

easiest way to check would be to look at the amp when the Jeep is off. I the amp as a power light on the the remote wire is connected to a constant power source. will need to rewire it to the remote swich in the head unit.

 

[cobrasatellite]

Just run a wire from a ign switched slot in the fuse box, to a switch, from the switch to the REM (remote controles turning on the amp) erminal on the amp. really easy takes about 15min. this will allow u to turn off the subs if u want. I have 2 12s in a sealed box with a 10 in a ported box and switching it off is the only way i can have a conversation with anyone with sterio on.