Engine Noise.

[CrownVic 15]

I recently installed another amp and some 6x9's in my car along with my existing sub amplifier, I have some obnoxious engine noise going on now that wasn't there or noticable before the install. My power wire and RCA's are ran on seperate sides of the car, The amps do have a common chassis ground in the trunk. Is the engine noise because of the shared ground? If you need anyother info please let me know. Thanks for the help.

[Spencerk 4]

well I would try and move the ground but if the sub amp isnt doing ti then I would think the same location would not be cause for concern. what kind of amp is it. I could be the amp internally or the out put from the deck could be bad.

[CrownVic 15]

My set up is in my sig. I've used both amps for the sub seperately with the same ground without issue.

[///M5 2,833]

<--nobody here hardly has sigs turned on, at least on the posts a lot team

Engine whine is 90% of the time ground related, the next big culprit is RCA's. It is never caused by what side you run them on though.

Either test each piece independently and let us know which piece has the problem or just start with pulling/making fresh grounds (make sure to brush down to bare metal) for every location. I'd start with the headunit.

And while you are at it, double check all your connections and make sure they are tight.

[CrownVic 15]

This is my ground now except there is another wire there also.

So start checking grounds at the headunit?

Im using the stock ground now if there is a better one someone please share.

[HiFonicsHorder1 5]

This is my ground now except there is another wire there also.

So start checking grounds at the headunit?

Im using the stock ground now if there is a better one someone please share.

I would move the ground also to the floor. There will be some places in the floor pan where you will see panels over lap each other so the metal is thicker. I also ALWAYS drill a small pilot hole regardless if it's a self tapper. The only other thing I would add is a external lock washer. It is serrated (basically cuts into the metal as you tighten the bolt.

Do you know how to do a voltage drop? If so I would check the ground now if you want.

My 2 cents

Good Luck

[jcarter1885 995]

That is a good ground(the way you set it up, clean the paint off and everything) just probably not a good grounding location. Either start at headunit or relocate your ground in your trunk. Grounding amps in the same location wont have this problem unless it is a bad location, so dont worry about if your ground your amps at the same location or a different one.

[jonbearsmt 919]

is it a pioneer deck???

also thats a weak ground...

[///M5 2,833]

Stock headunit grounds are regularly terrible. You also need to check to make sure that hinge is actually has minimal resistance to the neg batt connection.

[CrownVic 15]

Well i just got off work. I will check the H/U first. I noticed today that when on AUX mode the whine is signfigantly louder until i hook up my ipod. Also its coming from the alternator because you can hear the pitch change with engine speed. My dad seems to think its not a grounding issue and that i need a RF filter, but hes not a caraudio guy and that option costs money so im gonna try a different ground first for the H/U. And no its not a pioneer.

What is a voltage drop test and how do i do it. Also how do i check for minimal resistance.

I have a DMM but no O-scope so anything requiring that is out of the question.

Thanks for the help.

Edited January 4, 2010 by CrownVic

[CrownVic 15]

On another unrelated note, I have done the big 3 and now my voltage is at 14.8 at idle and doesnt dip below 14v with the acc. and lights on with music at full tilt but i still get some very noticable dimming. Is there a way to stop this?

Also to increase playing time with the engine off i was thinking about adding a seperate battery in the trunk. I was wondering what all is involved with this would i need a battery isolator or would i just wire it to the battery under the hood?

Sorry for the multiple questions but i have no one else that is knowledgable about car audio, and i didn't want to clutter the board with multiple topics.

[CrownVic 15]

Well i fixed it, I forgot to hookup the antenna and i guess thats what caused the noise but now its fixed.

[CrownVic 15]

well i thought it was fixed, its not.

[ABXX49 20]

well i thought it was fixed, its not.

Okay, well lets restart. Give us a full list of things that you have tried that don't work, and things that helped.

[CrownVic 15]

well now whats happening is on AUX mode the engine noise is present when the ipod is hooked up but not when its unhooked. I really only use the AUX mode so this is annoying as hell. I didn't check the grounds because i thought it was fixed. I cant work on it tonight though after work so it will be tomorrow before i can do anything.

[CrownVic 15]

Well Im sorry for the multiple posts but I guess i cant edit my posts after a certain amount of time.

Whats happening is now since ive hooked up the antenna the alt noise has quited but is still there getting louder with the volume. Ive heard that i need to redo the H/U ground, but my question is should i ground it somewhere in the dash or run a ground wire somewhere else?

[deathcloud 6]

not to thread hijack but now I am having this problem. It happened when I hooked up my sax100.4

The thing I am going to try is checking all my grounds ( I recently did the big 3 but I don't think my grounds are that good. The neg to chassis is tied into my strut tower. The neg to engine isn't necessarily attached to the engine)

anyways I guess I will check my ground on my headunit and see if that is the problem.

My ground in the trunk is attached to the seatbelt bolt. Is that a bad spot. I think Ive read that it is... maybe ill change that as well.

[Duran 387]

not to thread hijack but now I am having this problem. It happened when I hooked up my sax100.4

The thing I am going to try is checking all my grounds ( I recently did the big 3 but I don't think my grounds are that good. The neg to chassis is tied into my strut tower. The neg to engine isn't necessarily attached to the engine)

anyways I guess I will check my ground on my headunit and see if that is the problem.

My ground in the trunk is attached to the seatbelt bolt. Is that a bad spot. I think Ive read that it is... maybe ill change that as well.

Yup. Bad spot.

[deathcloud 6]

where is the best way to ground in the trunk? And what is the best place to ground under the hood? I did the strut tower but i dunno if it is the best. I couldn't find my engine ground where the factory engine ground went to.

[jcarter1885 995]

Why is the seat bolt a bad grounding location, I never had a problem grounding my amplifiers there? (just curious, maybe I have been doing wrong all this time).

[deathcloud 6]

Well I was watching some vids of grounds. And most people do it on the seatbolt belt in the rear seats. Mine has been cleaned off and sanded down.

But I did watch a video by elemental designs on where they did the ground. They took out the rear seats, then sanded down a spot in the frame, then took some screws and screwed down the 0/1 awg terminal into the frame. Thats it. I was thinking about doing this to see if it would make a difference.

One thing that I did was do a little trouble shooting today. At my battery I am reading with the car at idle 14.3-14.4

then at the rear at the amps I read 14.1-14.2 so there is a drop just from my run to the rear? wtf

Next thing I did was disconnect the saz-1000D, and just had the sax100.4 hooked up. The high pitched noise was gone. the alt whine i am guessing. Then when I hooked back up the saz-1000D and had both amps going it started making the noise again. So weird.

I don't know what that could be. I checked my grounds and they are all secure. Even the engine to neg is good. strut tower to neg is good. I dunno. I am lost.

[Impious 1,476]

Why is the seat bolt a bad grounding location, I never had a problem grounding my amplifiers there? (just curious, maybe I have been doing wrong all this time).

Several reasons. Many times they can be covered in gook which keeps from getting a solid connection. Some seatbelt bolts and seat bolts, while securely attached to the vehicle mechanically, don't have a great "electrical" connection to the rest of the vehicle. And depending upon how someone connects their terminal to the bolt, there may be very little contact area (if they install the terminal above carpet or padding, for example).

The short of it is, the quality of the connection can be hit or miss....so why take the chance? Create your own ground somewhere that you know will be a solid connection and bypass the entire possibility of having an issue.

You might not notice an issue (alt whine, etc) but that doesn't necessarily mean you have great ground.

[jcarter1885 995]

Well I do appreciate you for that bit of advice that you gave me, I have some adjustments to do now to my system. On my next build I was going to just ground everything to the battery.

[deathcloud 6]

Thx for the info. I guess I can change my ground. Make my own like they did in the elemental designs video. But I like jaycees idea as well. Maybe when I get the money for 0/1 awg again I can try to run it from my battery to the rear. But I would rather just try grounding it first to not the seatbelt area. lol.

[jcarter1885 995]

Why is the seat bolt a bad grounding location, I never had a problem grounding my amplifiers there? (just curious, maybe I have been doing wrong all this time).

Several reasons. Many times they can be covered in gook which keeps from getting a solid connection. Some seatbelt bolts and seat bolts, while securely attached to the vehicle mechanically, don't have a great "electrical" connection to the rest of the vehicle. And depending upon how someone connects their terminal to the bolt, there may be very little contact area (if they install the terminal above carpet or padding, for example).

The short of it is, the quality of the connection can be hit or miss....so why take the chance? Create your own ground somewhere that you know will be a solid connection and bypass the entire possibility of having an issue.

You might not notice an issue (alt whine, etc) but that doesn't necessarily mean you have great ground.

Well I just went out there and did a test on my grounds and I got a reading of 0.00-0.03 but it would stay at 0.01 or 0.00 ohms after jumping through numbers. I put one probe on the seat bolt itself and the other probe on the end of the ground wire that I took out from my amp. I did some research after searching through about 100 pages for that testing method and dont know if it is valid or not. If not could you lead me into a test where I can use my DMM to test resistance? If I did a good test then is my ground a good one? Thanks man, Im not to hip to this DMM thing so I dont know how to use it 100% yet.