Just a thought.... if your picture is saying you grounded your amp to the bolt that connects your amp to the chasis that might be your issue.....

 

These look like at least partially unshielded twisted pair to me (to show off the twist, of course!). If they're shielded except for the part by the end, probably not the source of noise though. I used double-shielded Tsunami brand RCAs on mine.



I'd recommend just getting a longer ground cable and using the seat belt anchor bolts.

 

Basically yes you are correct.

My amp is bolted to the factory bracket which is made of metal.

The bracket is bolted to the trunk floor with existing bolts that are embedded in the floor sticking up vertically and secured with nuts.

Yesterday morning my AMP Ground was bolted under the stock amp bracket then secured with a nut.

I have attached another crappy drawing for your pleasure to illustrate.

Yesterday afternoon my AMP Ground is now bolted to another bolt that is not being used anymore (because I cut off the corresponding leg of the stock amp bracket).

So basically either way the AMP Bracket is grounded (metal to metal) and may be grounding the amp as well since its bolted to the bracket).

I didn't think to try to insulate it but i defiantly will once I get home and see what happens.

AMP Installation MSPAINT Picture:



AMP Bracket (Real Picture) :

 

Wrathernaut, I highly doubt the RCAs are the issue based on his setup. But now looking at your amp mounting bracket and if I understand what you just posted I can be almost CERTAIN the grounding point is the issue. Either ground it to the seatbelt like Wrathernaut said or buy a self tapping screw and screw it into the metal behind the seat but not to the floor. *****Wrathernaut***** correct me if I'm wrong but the fuel tank is not under the rear seat???? In any case, just don't tap the screw where the fuel tank is, period! I can't look at my G at the moment. At work in a secure building. No cell phone either. 12 hour shifts blow!

 

Wrathernaut

If I use the Seat Belt Anchor Bolt I have 2 questions.

1. Does it require me to scrape paint

2. Is the bolt size small enough that I can use a Standard 4 Gauge Eyelet connector

Picture below (in case u know it as something else)

 

Also, the grounding the amp and the ground wire makes no sense lol I just think your ground is too close to your amp and that because the amp uses a metal bracket for mounting it's causing the whine.

 

SergeantRed & Wrathernaut

I will extend the Ground Wire and Mount it to either the seatbelt bolt or Ill screw it into the metal behind the seat.

I'll just need to purchase some more 4 gauge wire since my current 4 gauge wire will not be long enough to reach either location.

Do you think I need to insulate the metal legs of the amp bracket so that it inst directly connected to the metal floor of the G35?

SergeantRed I know what you mean I am at work as well (though not 12 hours shifts) so I cant go really take picture of the setup (At least maybe not until lunch if i can find a 10 mm socket ).

 

There would be two "possible" advantages here: by adding a couple rubber spacers between the amp bracket and the vehicle, you may eliminate the whine (although I still think it's the ground point itself) and vibration. Rubber spacers can't be more than $1-3 at Lowes.

 

SgtRed you replied faster than I could reply back but amp ground issue noted ill insulate it and see if it helps.

SgtRed and Wrathernaut Ill also extend ground to recommend places and see if that helps as well.

I much rather do either one of these before taking out that radio to change RCA's or run a long ground as that's a major P.I.T.A.

 

A long ground will not fix the problem, that I can assure you of......

On another note, I've taken my flippin dash apart at least 12 times so I can adjust and add crap! lol

 

Lol its not the taking the dash apart that's hard its the putting it back together part due to all the wires on the back of my headunit which does navigation so lots of wires including the standard ones.

Hey if I mount to seatbelt bolt should i still try and scrape it down to shiny metal or does that not matter as much for seatbelt bolts?

 

always scrape

 

Fuel tank is under the rear seat, but with the seat belt anchor bolts right there too, no reason to use a self-tapping screw. I doubt it's the RCAs as well, but just for any future purchases of people reading this - shielded RCAs > twisted pair in cars 99.9% of the time. (side note - I hate working in a SCIF too.)

As SGTRed said, scrape that paint! it's not exposed to the environment, it's not visible. Scrape it.

If the 4-gauge eyelet doesn't fit, just drill it out a little (use vise-grips or an actual vise to hold it while you drill).

Metal bracket could definitely be the problem. I've never really considered it, since I always mount my amps to MDF, not to metal.

 

SgtRed I took a ton of pictures yesterday but my next post following this one may be of more interest.

I wont spam you with pics (83 photos) but just attach the ones you requested.

I assume since the whole secured facility thing that If I attach inline with [IMG] Tags from dropbox you wont be able to see them so ill just upload them directly to G35Driver and attach that way.

Ok looks like I can only upload 5 files directly to G35Driver per post so I had a few more I wanted to show but guess I cant.

I measured the resistance of my old grounding point with a fluke meter. I have pics but cant put them in this post so youll have to trust my numbers.





Original Ground | Resistance Measured From Bare Metal at Grounding point on Body to Ground input at AMP | 0.4




New Ground | Resistance Measured From Bare Metal at Grounding point on Body to Ground input at AMP | 0.6

 

Here are some pics of things I could not attach in the last post.

Moving the Ground point did not make a difference in the electrical whine.