jasonsjwou

I have 05 Honda CRV. I have a 600watt amp installed, which is plagued with whining noise (that changes its pitch with the engine rev).

I was going to fix it after my two week vacation. I didn't drive the car for 19 days, then the car battery died. I had to jump start it. I never had any problem like this before I installed the amp. I could go for whole month and didn't have any problem srarting the car.

This time, I took it to a mechanic, who told me that the battery is dead - It won't hold the charges no more. I had to buy a new one.

Could bad ground that causes whining noise also cause the battery to drain over 3-4 week period?

Jason

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durwood

No. Bad grounds do not cause the battery to drain. Only if something is drawing power will it drain your battery.

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binary.h4x

Does the amp turn off when you turn off the vehicle?

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brodgar

A bad ground causes a resistance in the circuit which could affect battery charging.

The whining noise could be an earth loop. Ideally all audio components should be earthed to the same point. Suggest you clean all earth points

jasonsjwou

I think I know why I am getting ground problem.

The 600Watt amp, which is under the driver's seat, has its ground wire (8AWG) running back to the dash board area where it is connected to a distributor block, then is terminated on one of the chassis bracket.

the 8 AWG ground wire is about 4 feet run - from the drivers seat to the dashboard (right next to the steering colume joint) that's way too long.

I should get the wire directly terminating near the seat bracket area.

Correct?

Then where should I be terminating my Headunits at?

acidrainbw

dude.., i had the same problem on my old civic about 2 weeks ago. the battery would die after a couple of hours after jumpin it and a new battery would only last about a week before it needed its first jump. after about a week in a Honda shop a new alternator (which was only about a year old), 2 new batteries, and 300 bucks in shop costs, the problem was........ my after market alarm system. and that was a real shock cuz i really thought my sound system was the culprit. it really could be anything, so the best thing to do is just drop it off at a local shop and let them run a full diagnostic on it and save yourself alont of time, money and heartache.

scott_fx

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HyperZulu

You should still ground everything to the same spot probably. I think 8awg might be too small a guage of wire. Why not just buy another 4awg 4' wire? That's what I'm running on my 600w amp going back at least 10' with no problems.

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jasonsjwou

Where should I ground the head unit?

I've got two headunits - One is 7" monitor DVD player, the other one is HDD based Divx/MP3 player. Both are taking its power from the stock OEM power line.

How much does the RCA interconnect affect ground loop? (Alternator Whine) I've got a "Diesel Audio" interconnect that is about 3 feet longer than what I really need.

I grounded my amplifier with a short (about 10 inch) 4AWG wire, directly to the chassis screw under the seat.

It reduced the alternator whine, but it is still there. I can hear it.

So, all of you experts outthere...

If you have two headunits and one 600watt amp under the seat, how would you wire everything up?

toughluck78

In a perfect world, everything would get it's power and ground from the same point and we'd all be on our merry way It's better to have everything grounded to the same distribution block, rather than an amp be grounded in one spot, and the deck another (I'm off today, and bored, so I'll offer a short explanation as to why at the bottom of the post, if you're interested ). 8 Gauge is a little small for 600W, and I'd jump up to 4 Gauge and ground everything to the same block. Everything.

Turn on your car and measure the voltages between your power and grounds at the battery, Amplifiers, the Deck, and the Computer. If there's a difference of about 1/2 volt or more, you'll most likely induce noise into the system.

Usually the noise is going to get introduced between the deck and the amp. If you mute the radio and the noise is still there, that's whats happening. An easy way to minimize this is to lower the gain of your amplifier, and raise output of your stereo. Turn the amplifier all the way down, then crank the deck almost to max volume. Then, turn your amplifier up to your maximum listening volume. By doing this, you're minimizing how much the noise gets amplified.

Also, some AC current stays in your car's power system, so be sure not to run your RCA cables next to your power/ground wires or you'll induce noise into the system.


Hope it helps.


*A quick simple partial explanation for everything being grounded to the same point. One grounding point might have a few more Ohms of resistance in the circuit than the other one, which makes current flow it's own little circuit, in a loop from say the amplifier ground, through the chassis to the Radio ground, and back through the RCA plugs and it causes a hum, and that's called a Ground Loop. It's much more common in fixed system such as your house than your cars, but it does happen.
The reason is you're simply running the power and RCA lines too close to one another.

Here is a loose guide for power requirements vs cable

Power Wire Gauge Guide
Total Power 15 Ft 17 Ft 20 Ft 22 Ft 25 Ft
100 Watts 10 10 10 10 8
200 Watts 8 8 8 8 8
300 Watts 8 4 or 8 4 or 8 4 or 8 4 or 8
400 Watts 4 or 8 4 4 4 4
500 Watts 4 4 2 or 4 2 or 4 2 or 4
600 Watts 4 2 or 4 2 2 2
700 Watts 4 2 or 4 2 2 2 or 1/0
800 Watts 2 or 4 2 2 2 or 1/0 1/0
900 Watts 2 2 or 1/0 1/0 1/0
1000 Watts 2 2 1/0 1/0 1/0

All wires in AWG

PugFunk

as asked before you didnt give answer.

Does everything switch off once your car is off?

Nothing should be on while your car is switched off. If it is it means that you have connected your trigger wires to 12volt constant. You need to connect all your trigger wires to the ignition wires.

Everything should be off..... make sure you check everything.

Maybe something you have has a hibernation mode? such as a computer and its not switched off.

Alarms should not draw very much power at all. Alarms are most of the time a passive unit and detect possitive pulses through the wires they are tapped into. They dont just sit there drawing power. Pritty much the only thing sucking power in an alarm is the flashing LED and the alarm itself charging a backup battery if it has one. Everything else does not draw power until the alarm has been activated.

The whine is to do with not enough grounding. As said before ground everything to a seperate point. If its under your seat ground it to the seat frame. Just make sure you sand off some of the paint first to ground to bare metal.

Also upgrade your ground strap from your (-) battery terminal to chasis under the bonnet.

PugFunk

I would be running your own power cord directally to the battery for your extra deck. The current cords are probably not thick enough to draw that much power.

Its not worth risking running them both off the same OEM cable as it may cause it to heat up enough to cause a fire.

Treat it like an amp. Run a cable from the battery, make sure you use a fuse close to the battery. Run it into the cabin through the firewall. Under the carpet or centre console and then under the seat. Making sure the wires will not be pinched when the seat moves.

While your at it. Put a distribution block in your amp (deck/LCD screen) cable behind the dash. That way you can use that power cord for your screens and your deck(s) as well as any future upgrades.

Keypoints
-Upgrade power cable to reduce resistence and heating of the current power cable

-upgrade your ground from (-) terminal on battery to chasis

-Make sure you use a fuse

-With 2 screens you may need a battery upgrade to a high power battery as well as a alternator upgrade if your current one does not produce enough to power all of this system as well as recharge your battery

monkeyracer

This is for the RMS (constant) rating of the amp, not the max ratings. The OP has a "600W" amp, or at least that's what the marketing department had printed on it. The OP probably has a 300w RMS amp, so according to the above, he'd be fine, But I do still recommend upgrading the wire. Also, make sure that the ground is touching the metal very securely, scrape the paint away, etc. And check to make sure the amp light turns off with the vehicle, otherwise as PugFunk said, you could have it connected to 12v constant, rather than acc switched.

Lastly, stupid thing that was up with my car: the door ajar sensor was all messed up and the interior lights would stay on. All the doors were closed, and closed again just to make sure. This went on for about a month before I found out what was up. (luckily my car has a low voltage shut off built in, so it didn't completely drain the batt.) I searched forum after forum, and found that my make/model had an issue with the sensor getting gunked up, wd-40 sprayed on it, and it's been fine ever since.

The moral being that it could be something totally stupid.

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