too many grounds
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=95857
Printed Date: May 19, 2024 at 6:55 PM
Topic: too many grounds
Posted By: hamzter
Subject: too many grounds
Date Posted: July 23, 2007 at 9:44 PM
Well, I got off the phone with Eclipse TS and the tech wants me to upgrade my 8 ga grounds in my engine compartment to 4 gauge.
Is it possible to have too many grounds in the engine compartment and it create engine noise in the audio system?
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Mark "Hamzter" Cinense
1991 Infiniti G20 w/JDM SR20DE
Eclipse CD8445
MTX Thunder 684
Polk DB6750
Polk DB6500
Optima Red Top in the Trunk
Replies:
Posted By: haemphyst
Date Posted: July 23, 2007 at 9:55 PM
No. As a suggestion, though, make sure you CREATE as many ground points as you can, don't connect multiple cables to one bolt.
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: jmelton86
Date Posted: July 23, 2007 at 9:58 PM
Isn't it the opposite, too little grounds create noise? I mean, I always knew that more grounds is better...
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2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Posted By: hamzter
Date Posted: July 23, 2007 at 9:58 PM
haemphyst wrote:
No. As a suggestion, though, make sure you CREATE as many ground points as you can, don't connect multiple cables to one bolt.
is that the same as one cable to 2 different points? I may have one like that in the engine compartment. If I do, I can quickly change it.
you mean create as many different ground points in the engine compartment? ------------- Mark "Hamzter" Cinense
1991 Infiniti G20 w/JDM SR20DE
Eclipse CD8445
MTX Thunder 684
Polk DB6750
Polk DB6500
Optima Red Top in the Trunk
Posted By: aznboi3644
Date Posted: July 23, 2007 at 11:32 PM
I upgraded as many grounds as I could find in my engine compartment.
Battery ground to body
Battery ground to frame
Battery ground to engine block
Alternator case to engine block
Then a few grounds underneath the chassis grounding the body to the frame
lol
Posted By: haemphyst
Date Posted: July 24, 2007 at 7:54 AM
The more points of proper electrical contact you have, the closer to a homogenous ground plane you will get.
The homogenous ground plane is what you are looking for, here.
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: hamzter
Date Posted: July 24, 2007 at 7:57 AM
haemphyst wrote:
The more points of proper electrical contact you have, the closer to a homogenous ground plane you will get.
The homogenous ground plane is what you are looking for, here.
so in the engine compartment, should I add a couple more short 4 gauge wires to ground from the motor?
I will do that... but what the Eclipse Tech said about having 1 gauge ground from the motor only did not make sense to me. ------------- Mark "Hamzter" Cinense
1991 Infiniti G20 w/JDM SR20DE
Eclipse CD8445
MTX Thunder 684
Polk DB6750
Polk DB6500
Optima Red Top in the Trunk
Posted By: haemphyst
Date Posted: July 24, 2007 at 9:19 AM
It couldn't hurt... I think the 1/0 is a bit overkill, though...
WTH?!?! DAVE said someting was OVERKILL?!?!  
(I re-read your post, and you typed that the tech said 1 gauge, not 1/0. Is that what he said? Two #4 wires is the same MCM as a single #1, but NOT the same as a 1/0. IMO, two #4 wires, attached between the engine block and chassis in two different places on both ends would be more effective than a single #1 cable.) ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: hamzter
Date Posted: July 24, 2007 at 9:24 AM
I have 1 gauge in the trunk for negative to chassis.
I will add more ground in the engine compartment in the next day. I don't think that will solve my engine noise problem, but I hope I at least see a difference in electrical power... ------------- Mark "Hamzter" Cinense
1991 Infiniti G20 w/JDM SR20DE
Eclipse CD8445
MTX Thunder 684
Polk DB6750
Polk DB6500
Optima Red Top in the Trunk
Posted By: forbidden
Date Posted: July 24, 2007 at 2:46 PM
You should be seeing a difference. It is all about making the flow of current as efficient as possible. Current starts at the alternator, alternator is grounded to the engine. This is why the tech guy told you to upgrade the ground from the engine to the chassis. Current needs both a + and a - to flow properly. Restrict one and it restrics the flow of current.
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Top Secret, I can tell you but then my wife will kill me.
Posted By: hamzter
Date Posted: July 24, 2007 at 2:52 PM
forbidden wrote:
You should be seeing a difference. It is all about making the flow of current as efficient as possible. Current starts at the alternator, alternator is grounded to the engine. This is why the tech guy told you to upgrade the ground from the engine to the chassis. Current needs both a + and a - to flow properly. Restrict one and it restrics the flow of current.
that totally makes a lot of sense, but would this improve or eliminate engine noise? I am going to add a couple of 4 gauges to the motor in the engine compartment...
I think it would be good, but to tell me that it can affect your engine noise by not having large enough gauge... I need an explanation.
------------- Mark "Hamzter" Cinense
1991 Infiniti G20 w/JDM SR20DE
Eclipse CD8445
MTX Thunder 684
Polk DB6750
Polk DB6500
Optima Red Top in the Trunk
Posted By: hamzter
Date Posted: July 24, 2007 at 11:20 PM
I added one more 4 gauge ground in the engine bay... no help with the noise...
I will add probably 2 more 4 gauge cables to the motor for ground and call it a day on the grounds in the engine and chassis.
I may have to look at another headunit sometime in August.
-------------
Mark "Hamzter" Cinense
1991 Infiniti G20 w/JDM SR20DE
Eclipse CD8445
MTX Thunder 684
Polk DB6750
Polk DB6500
Optima Red Top in the Trunk
Posted By: mjwood0
Date Posted: July 25, 2007 at 5:02 AM
With all the issues you seem to be having with noise, have you insured that your ground point in your trunk with you amp and battery is good? Grounding to the body isn't always the same as grounding to the frame. Often, cars will isolate the body from the frame for road noise / vibration reasons. They should still be tied together with grounding straps, but you never know. Same could be said for the head unit. I would double check the grounds all around. If possible, check continuity between the alternator ground (engine usually) and the components.
Just a thought. If this has been covered in other posts already, sorry for the duplication.
Posted By: haemphyst
Date Posted: July 25, 2007 at 7:27 AM
I'm just seeing (in your sig) that you have an additional component... the crossover. Have you bypassed this to confirm it's NOT that?
You seem to be fixated on the HU and the grounding aspects of all of this, but I can't recall you saying anything about the Memphis piece...
hamzter wrote:
I think it would be good, but to tell me that it can affect your engine noise by not having large enough gauge... I need an explanation.
If you have a HUGE power cable, but you don't allow for an equivalent or LARGER return path, if you are using all of the capacity of the power side, the current will try to find ANY WAY IT CAN to get back to the battery, and that means RCA shields, possibly causing noise... ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: hamzter
Date Posted: July 25, 2007 at 7:42 AM
haemphyst wrote:
I'm just seeing (in your sig) that you have an additional component... the crossover. Have you bypassed this to confirm it's NOT that?
You seem to be fixated on the HU and the grounding aspects of all of this, but I can't recall you saying anything about the Memphis piece...
noise...
I did earlier in my tests bypass the crossover and go straight to the amp. I have had 2 electronic crossovers and noise is present in the system with both.
I see that mjwood0 asked if I had checked the ground on the body, and I have. My battery is in the trunk and I think I am getting a good solid ground. Otherwise I think other components would be failing outside of the audio system.
So, I could strap a ground to the main ground point where the battery is and the frame. I will be adding at least 2 more 4 gauge grounds from the engine to chassis.
------------- Mark "Hamzter" Cinense
1991 Infiniti G20 w/JDM SR20DE
Eclipse CD8445
MTX Thunder 684
Polk DB6750
Polk DB6500
Optima Red Top in the Trunk
Posted By: haemphyst
Date Posted: July 25, 2007 at 10:07 AM
So, the deck is the LAST thing you need to replace or swap? Have you tried powering the deck from the same battery as the amplifiers? By that, I mean actually running a 12 or possibly a 10 gauge speaker or power wire back to the rear battery? You will only need it for power and ground, as the accessory lead is still referenced to the chassis ground, it'll still work with the key. Also, I HAVE seen noise on the accessory lead induce noise in a head unit, but it's exceptionally rare. If you still get noise, try running another wire for the accessory to the rear battery, just for diagnostic purposes. If it fixes it, THEN we can work on getting you a solution to fix the accessory wire.
From what I have read so far, it seems you have tried everything, except providing a signal from an isolated source, i.e. iPos, or walkman of some sort, or:
Have you tried powering the deck while it's NOT in the dash? Have you actually connected it to the amplifiers in the back, while it is physically located in the back, and powered off the rear battery? Try that, making sure the deck remains isolated from the chassis, and powered COMPLETELY off the rear battery.
Beyond that... dude, you've done EVERYTHING I'd've done, in a troubleshooting session.
-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: mjwood0
Date Posted: July 25, 2007 at 10:14 AM
hamzter wrote:
So, I could strap a ground to the main ground point where the battery is and the frame. I will be adding at least 2 more 4 gauge grounds from the engine to chassis.
I think there is an important distinction to be made here. The chassis (frame) of the vehicle is not the same as the body (sheet metal) of the vehicle. Nor is the engine ground the same as the chassis ground. Ideally, all these should be tied together properly to make them one ground.
I believe your power should be flowing as follows:
Alternator --> through cable to battery --> through wire to second battery in trunk -- > through wire to amplifier.
From here, the amp, speakers, etc draw power.
There needs to be a return path at basically all points here. My guess is that your return path actually looks like this:
Amp --> through wire to body (sheetmetal) --> through ground strap to chassis (frame) --> through ground strap to engine --> through alternator mount to alternator.
You can verify the relative strength of all of these by measuring the resistance from the amp ground output to the alternator bolt where it connects to the engine. If you have low resistance, your ground path is good. What "low resistance" is really depends. Larger gauge wires are always good for high current applications.
Good luck! Hope this all makes sense!
Posted By: hamzter
Date Posted: July 25, 2007 at 10:41 AM
haemphyst wrote:
So, the deck is the LAST thing you need to replace or swap? Have you tried powering the deck from the same battery as the amplifiers? By that, I mean actually running a 12 or possibly a 10 gauge speaker or power wire back to the rear battery? You will only need it for power and ground, as the accessory lead is still referenced to the chassis ground, it'll still work with the key. Also, I HAVE seen noise on the accessory lead induce noise in a head unit, but it's exceptionally rare. If you still get noise, try running another wire for the accessory to the rear battery, just for diagnostic purposes. If it fixes it, THEN we can work on getting you a solution to fix the accessory wire.
From what I have read so far, it seems you have tried everything, except providing a signal from an isolated source, i.e. iPos, or walkman of some sort, or:
Have you tried powering the deck while it's NOT in the dash? Have you actually connected it to the amplifiers in the back, while it is physically located in the back, and powered off the rear battery? Try that, making sure the deck remains isolated from the chassis, and powered COMPLETELY off the rear battery.
Beyond that... dude, you've done EVERYTHING I'd've done, in a troubleshooting session.
I have isolated the deck, and I don't get any noise while the car is running.
with that said, I have tried the deck when not in the dash. My battery that is in the trunk is the only battery I have.
I have done the resistance check on the cable and the devices.
I also have a separate 10 gauge set going from the HU to the trunk where the battery is. So like I said, the noise only happens when the car is on.
I tried connecting the ground wire back to the chassis of the radio and then mounting the radio to the dash. Keep in mind the dash where the radio mounts is a steel frame then covered with plastic. I can get the noise down to a minimum by disconnecting ground and mounting the radio to the dash/console.
I also did an iPod test and with the car on and the source connected to the Electronic Crossover or directly to the amp and no noise present...
So, you think it could be the HU? ------------- Mark "Hamzter" Cinense
1991 Infiniti G20 w/JDM SR20DE
Eclipse CD8445
MTX Thunder 684
Polk DB6750
Polk DB6500
Optima Red Top in the Trunk
Posted By: haemphyst
Date Posted: July 25, 2007 at 12:06 PM
hamzter wrote:
So, you think it could be the HU?
Well, if you have done all of that, and with all of the grounding efforts you have taken, I'd have to say yes, the deck is your offending component.
Before you actually dump cash on another deck, see if you can borrow one from somebody... (Actually I HAVE an older Eclipse 8051 - the CD doesn't always want to load or unload perfectly, but...)
You have PM. ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: haemphyst
Date Posted: August 05, 2007 at 9:30 AM
Mark,
New input from DYohn. I mentioned to him the fact that you have no noise (or effectively no noise) when the radio is out of the dash, but that it shows up as soon as you screw the ears in. He said your ECU is the issue.
What he suggested is that you unscrew the ECU from its moorings, and see if the noise goes away THAT way, as well. If so, you'll need to either:
1: Replace the ECU, (possibly a performance programmed item, so probably not a truly feasable option) or...
2: Figure someway to isolate the ECU from chassis ground, and use JUST the ground wire on the ECU's power plug
Neither way will be easy, but the isolation route will CERTAINLY be cheaper... :)
Knowing that you've got all those performance parts in that car, was the ECU switched or modified in any way that you're aware of, or is it a stock ECU?
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: DYohn
Date Posted: August 05, 2007 at 10:54 AM
Yea, I said that because I have seen it happen many times and it is worth checking out, especially if the car has been chipped. But if this car is as heavily modified as you say it is, the source could be anything. ------------- Support the12volt.com
Posted By: hamzter
Date Posted: August 05, 2007 at 12:11 PM
haemphyst wrote:
Mark,
1: Replace the ECU, (possibly a performance programmed item, so probably not a truly feasable option) or...
2: Figure someway to isolate the ECU from chassis ground, and use JUST the ground wire on the ECU's power plug
Neither way will be easy, but the isolation route will CERTAINLY be cheaper... :)
Knowing that you've got all those performance parts in that car, was the ECU switched or modified in any way that you're aware of, or is it a stock ECU?
David,
thanks again for the hospitality. My wife and I enjoyed hanging out with you...
The ECU right now is stock until we boost the car... when??? unknown...
I had a bad feeling that the ECU would be the problem to my noise...
so, even if I re-run my RCAs I will still hear noise? I can remove the screws to the ECU if there are any.
Funny thing is that sometimes the noise is there and sometimes it is gone...
The G rides rough, and as you saw, the motor mounts totally vibrate the car. I don't know if that extra vibration is messing up the HU in some way.
DYohn] wrote:
Yea, I said that because I have seen it happen many times and it is worth checking out, especially if the car has been chipped. But if this car is as heavily modified as you say it is, the source could be anything.
Yes, the G has performance mods, but no CHIP, no performance mods that involve electricity except for grounds from motor to chassis.
We are back in Albuquerque, so, this weekend I will work on the system... wish me luck.
------------- Mark "Hamzter" Cinense
1991 Infiniti G20 w/JDM SR20DE
Eclipse CD8445
MTX Thunder 684
Polk DB6750
Polk DB6500
Optima Red Top in the Trunk
Posted By: haemphyst
Date Posted: August 05, 2007 at 1:45 PM
Enjoyed thoroughly having you here! Next time you're in Cali, look me up again! Loved the chat!
Well, short of what we already did... I got nothin'. POSSIBLY re-running the RCA's, but if the ECU is what's causing the problem in the chassis, then no re-running in the world will help!
Good luck!
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
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