5th Gen grounding issues

[nutsadamus]

wassup? My question is for those 5th gen owners with aftermarket stereos, how did you wire your dang system and not get engine noise? I've had this problem ever since removing the stock system almost 10 years ago, wrestled with it constantly, and finally decided to just mask the problem with a ground loop isolator. I've had 3-4 different amps and a few different headunits during that time and the noise remained consistent unless some type of ground lifter was placed inline. I'm back to the point where i want to fix the issue instead of just masking it.

I realize the problem is probably being caused by a bad ground .Shorting the rca inputs to the amp eliminates the noise. Audio and power/ground cables are running on opppsite sides of the car. The hu is grounded to the frame near the passengers side left leg, the amplifier is mounted to the rear seat and I used 4gauge wire to ground it to a bolt behind the rear seat which I sanded down to bare metal 1st. There are 2 cables from the negative battery terminal, one to the alternator, and a very short 4 gauge cable is attached to the chasis.

Should i ground the headunit and amp to the same spot? I've heard conflicting advice on various forums about running a ground cable from the -battery terminal all the way to a point in the trunk for the amp. Who to listen to? What do you guys do?

thanks for your help.

[vabapesta]

u should be able to ground your headunit using the existing radio harness in the car ....the best way to ground your amp is by finding a flat metal area somewhere no more than 1 foot away from the amp,scrape the paint off completely around the area you are going to ground to, use a ring terminal and crimp it to the end of your ground wire, use a short self tapping screw and a metal star washer that will bite into the metal when tightened down, and just make sure your not gonna drill into anything other than metal. do not ground to you battery or anywhere in the engine its to far away from the amp and would not be safe...that should take care of it if u still get engine noise after that then u have a different problem..

[nutsadamus]

Thanks, took a couple tries but i finally found a decent spot behind the rear seat. But now i realize that the ground wasn't the problem afterall. I should have done this alot sooner, but I finally unplugged the rca's from the hu going into the amp and plugged in my ipod. Noise is gone.

I'll check the rca's on the hu end, and determine if the cables need to be replaced/rerun/whatever.

May I ask what route you took when ruuning your rca's to the back? Mine are going down the driver's side lower door trim area i believe. Didn't want to go down the middle originally, but I might try that and see if it helps.

[vabapesta]

i went down the passengers side ... do not go down the middle... bring them up under the rear seats.. make sure you get a good set of rcas with some shielding on them.. go to a car audio shop to get them..u probaly spend about 50 bucks but their worth it..

[nevrdun]

Plugging in an Ipod is actually very clever of you. Most wouldn't have that kind of trouble shooting skill...BUT! Before you go buy an outrageously expensive RCA with more features that no one knows anything about or cares about that I sell go to Radio shack and buy a couple female/female barrel connectors and plug your ipod in at the head unit end of the RCAs. If you have no noise dont buy new RCAs and spend time running them. It sounds like a head unit issue. What kind is it? Also, don't be afraid of a ground loop isolator they are a bandaid but hey if it works...

[nutsadamus]

Thanks guys for the help...

I've made an interesting discovery, when I unplug the rca from the headunit side most of my alt whine goes away but it can still be heard faintly. So, even with no rca's plugged in, i hear a little something. Again, it seems as though I've been barking up the wrong tree, to me this seems to point to an issues with my front speaker wires.

When i first installed my stereo, i didn't really want to deal with trying to run fresh speaker cable thru the doors, so instead I spliced into the stock cables going into Honda's wiring harness.

I guess my next step is to cut the existing splice behind the hu, and re-splice in some fresh speaker cable directly from the amp (without running it yet) and see if the noise goes away.

Did you guys have any issues feeding speaker cable to the doors? How did you run it?

Thanks again for your feedback :)

[nevrdun]

Uh yeah running new wires into the door is no bueno! I havent done it yet and your still barking up the wrong tree. I have never heard of engine noise originating after the amplification circuits. If hyou can unplug the rcas and have noise it sounds like bad amp. or bad grounding point. You are grounded with a screw into bare metal that is a good peice of body structure right? Not something bolted to the body?

[nutsadamus]

finally, problem solved. Just a stupid wiring issue on my part at the hu harness.

What a relief.