good ground for amp on 2005 altima 2.5s

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Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=98510
Printed Date: May 01, 2024 at 8:52 PM

Topic: good ground for amp on 2005 altima 2.5s

Posted By: trancelovin65
Subject: good ground for amp on 2005 altima 2.5s
Date Posted: November 01, 2007 at 12:00 AM

Hi all, I just ran 0 gauge wire to power my amps, The ground I'm currently using is under the back seat straped to the oem bolt. I was wondering if someone would know if there is a better ground, cause the ground I have is not that great. thanks in advance.

Replies:

Posted By: i am an idiot
Date Posted: November 01, 2007 at 6:33 AM

3 Inches any direction from the seat bolt will probably work. But you must remove ALL of the paint from a spot, sandpaper, die grinder or dremel tool, your choice. To get the best and most reliable ground possibe you will need to get several 8 Ga. ring terminals, Strip about 4 inches of insulation off of the 0 Ga. wire and seperate the wire into bundles small enough to fit into the 8 Ga. ring terminals and crimp or solder them on the wire. Repeat till you have oll of the wire in ring terminals. You will have to sand the paint off of an area large enough to mount all of the ring terminals. BEFORE you sand the area make sure you will not be screwing through anything on the other side of the metal. Get some self tapping screws and star washers from the hardware store and a cordless screwdriver or a drill with a screwdriver bit. The ring terminal needs to be next to the chassis of car then the star washer on top of the ring. Or a split washer the washer is only used as a lock washer. Check to make sure the screws are all tight once a week for a month or so. If none have rattled loose in that time you will be OK but if they have you will need to check them regularly. Oh yeah don't listen to it too loud you WILL go deaf.

Posted By: coppellstereo
Date Posted: November 01, 2007 at 1:28 PM

Did you figure your grounding issue out?
When I ground something I look for factory welds. They look like little circles in the metal. I find two or three and then shoot a screw in between them. That way you know your screw went through more than 1 layer of metal and will stay more secure.

Be sure to look under the car for brake lines and other things that you dont want to puncture!

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Posted By: jrod83
Date Posted: November 01, 2007 at 2:50 PM

The factory welds are sometimes a little tricky. It looks like a weld but sometimes its that plastic stuff they use to bond the cars parts together. Just check the the spot you choose for a ground, test it and make sure it reads 0 ohms.

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MECP Certified
I am the loudest and proudest member of the Fighting Aggies Class of '11 WHOOP!

SAW 'EM OFF!

Posted By: donpisto
Date Posted: November 16, 2007 at 5:32 PM

i am an idiot wrote:

3 Inches any direction from the seat bolt will probably work. But you must remove ALL of the paint from a spot, sandpaper, die grinder or dremel tool, your choice. To get the best and most reliable ground possibe you will need to get several 8 Ga. ring terminals, Strip about 4 inches of insulation off of the 0 Ga. wire and seperate the wire into bundles small enough to fit into the 8 Ga. ring terminals and crimp or solder them on the wire. Repeat till you have oll of the wire in ring terminals. You will have to sand the paint off of an area large enough to mount all of the ring terminals. BEFORE you sand the area make sure you will not be screwing through anything on the other side of the metal. Get some self tapping screws and star washers from the hardware store and a cordless screwdriver or a drill with a screwdriver bit. The ring terminal needs to be next to the chassis of car then the star washer on top of the ring. Or a split washer the washer is only used as a lock washer. Check to make sure the screws are all tight once a week for a month or so. If none have rattled loose in that time you will be OK but if they have you will need to check them regularly. Oh yeah don't listen to it too loud you WILL go deaf.

Please explain how the bolded sentence is true. With all my installs of 1/0 wire I have used 1/0 ring terminals and never had a problem. Using several 8 awg ring terminals is pointless and unnecessary. It's more efficient to use a single 1/0 terminal. I would also recommend using copper lugs for the ground and other connections, such as those to the batter and whatnot, better conductor than those gold, platinum, etc plated ones. Also it should be bolted directly to the chassis. Scraping off the paint as you mentioned is defintely the way to go...just don't take your vehicle to best buy because they are not allowed to scrape off your paint. Most people don't realize that and don't have as good of a ground as they could have.

Posted By: fknfbm
Date Posted: November 16, 2007 at 10:58 PM

[/QUOTE]

You please tell me how the bolded sentence is true? Ive been working for bestbuy for a good while now and I know for a fact that this isnt true... I hate when people believe stupid myths.

Posted By: donpisto
Date Posted: November 17, 2007 at 4:28 AM

At best buy, at least from the ones I have been to and the ones that I know people work at, you're not allowed to scrape off the paint from the chassis. If you do not scrape the paint off the chassis, remove everything from it, sand it down, and make sure you are getting direct metal to metal contact, you will not get a good ground. It's as simple as using a DMM, and not a cheap one. I used to use a Sears one, and a Wal Mart one, but decided to toss in 80 bucks for a Fluke and readings are much more accurate. Anywho, you put the meter on resistance and test the ground. A reading of 0 is a perfect ground. I would find .1 and .2 to be acceptable, and possibly even .3. Anything above that, I would highly recommend a good ground. There are many issues that can arise from a weak ground.

Posted By: donpisto
Date Posted: November 17, 2007 at 4:39 AM

Next time I find myself at Best Buy, I'll be sure to head over to the installer's area and ask them. From my experience, the majority of the time the people who work at Best Buy don't know what they're talking about. I do know a couple people that work there and they do know their material, but for the majority, I cannot say this is true.

On numerous occasions I overhear sales reps misinforming the consumer. I've had a couple of them who had no idea what I was talking about. I initially go in to see if they had any Pioneer Premier decks, turns out they didn't, but the guy wanted to know what I was running. I mentioned Boston Acoustic mids, Treo amps, and a Digital Designs sub (this was like 5 setups ago, so probably about 8 or 9 months ago). The guy looked really confused so I said "Thanks for your help" politely and walked away. Could have easily been a d-bag, but there is no point of that. Again, I'm not trying to stir up an argument, I'm stating personal experience, not hearsay. Best Buy isn't the only place, I've seen it happen at Circuit and even at car audio shops.

At a local audio shop, my Treo SSX 1500.1 had blown and the guy said it's not worth fixing, yet I look around and see him selling Audiobahn. It ended up costing $200 to repair the amp but was definitely worth it, especially for it costing over a grand brand new (not what I would have paid though). I also had another shop tell me this Hitron EQ was just as good as an Audiocontrol and that it was $100 cheaper...well there is a reason, the Audiocontrol is actually better and has more features. Again, some people just don't know and I'd rather teach someone rather than make fun of them. I'm not audio genius, I still have plenty to learn, but its nice to have people teach you. I like to give back what was given to me, but someone being ignorant and telling me my equipment is junk just because they haven't heard the brand is absurd.

Posted By: raydawg357
Date Posted: November 20, 2007 at 10:41 AM

Donpisto- I don't know what clowns you are dealing with at Best Buy, but you are far from the truth. They are required to scrape to paint away from grounding points.

As far as the sales flloor person, I agree, they don't know what they're talking about majority of the time.

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Do it right the first time

Posted By: boogeyman
Date Posted: November 20, 2007 at 12:34 PM

This is an old GM Technical Service Bulletin, but it should help anyone wanting to verify that their amp has a good ground:

METHOD OF VERIFYING ' GOOD ELECTRICAL SYSTEM GROUND ' #87-8-139 - (04/07/1987)
VEHICLES AFFECTED: ALL MODELS

When diagnosing electronic systems for incorrect operation, it is often necessary to verify that ground circuits are good. This article is intended to clarify what is meant by the term "good ground" and the preferred tools and methods for verifying it.

A "good ground" is a ground circuit that has a resistance of zero OHMS.

Ground circuit resistance can be measured in OHMS using a digital volt OHM meter (DVOM). When using a DVOM, it must be set on the 200 OHM scale to obtain an accurate measure of the circuit resistance. Many meters have both a 200 OHM scale and a 200 K scale. The 200 K scale will not measure zero OHMS accurately. If you are not sure how the meter is to be set for the 200 OHM scale, refer to the meter operating instructions for proper settings. If the meter is an autoranging or self-scaling meter, read the meter carefully to be sure which scale it is setting itself to.

Before measuring resistance in any circuit, the resistance of the meter should be measured by touching the leads together. A meter with a good battery and leads in good condition will read less than .2 OHMS usually zero. If the leads measure anything more, an accurate measure of the circuit resistance may not be possible.

Always remember - resistance cannot be measured accurately on a "live" circuit, All current flow through a circuit must be stopped by disconnecting its power source before measuring resistance.

Ground circuit resistance can also be checked by measuring the voltage drop across the circuit with a DVOM set on, the 2 volt scale. The voltage drop will be zero across a "good ground" circuit.

Remember, fully understand a meter's functions before using it!

To add to this, a good ground for car audio applications will have a return resistance reading of 1/2 ohm or less. I have yet to have a return reading of 0 ohms. If a ground return reading cannot be made to get below 1/2 ohm by means of the "BIG 3", then it is adviseable to ground direct to the battery. Electricity is an algebra equation, what you do to one side you must do to the other. Pay as much attention to the ground wire as you do the power wire.

The BIG 3 is a great place to start for a good ground, however it is the assumed proper method of grounding. What we are talking about here is the older and wiser 4th brother to the BIG 3 (the BIG 4).

So a proper ground wire will be as follows.

- clean of residue and paint.

- secure.

- have a resistance return of 1/2 ohm or less.

- be of adequate guage to carry the return as compared to the power wire.

To simplify the measuring of the return, use your meter as described. Disconnect the - battery terminal and disconnect the ground wire from you amp. If your dmm probes are not long enough, you will need to create a jumper extension out of some primary wire or whatever wire you have handy. Measure this wire for any resistance reading and subtract it from the total.

Many installers are not aware of this nor practice this method. It takes time and time = $ so don't get all wizy if you had a professional install done and this was not checked. A poor ground connection or high resistance reading may seem trivial under no load, but once you are pounding your nice new amp and it is drawing large amounts of current, this little reading has become a monster reading that has caused many an amp to fail for no apparent reason. It may be noticeable as a extremely hot running amplifier in a short time period, poor output levels or diminishing levels and of course a blown power supply or output section in the amplifier.

While the original article was written for the years gone by, it still is applicable to the newer generation of vehicles. A good ground is not about the amount or size of the metal in the return to the battery but about the resistance through it. Todays vehicles are a combination of metals, spot welds, glued together unibody panels and isolated chassis components. The return through these components is where the resistance reading comes into question and this is what we need people to understand, why the BIG 4 needs to be done if the BIG 3 does not solve the problem.

Posted By: donpisto
Date Posted: November 21, 2007 at 1:21 PM

raydawg357 wrote:

Donpisto- I don't know what clowns you are dealing with at Best Buy, but you are far from the truth. They are required to scrape to paint away from grounding points.
As far as the sales flloor person, I agree, they don't know what they're talking about majority of the time.

I apologize for my fallacy. What may be true of one location may not be true of others. I'm gonna go to my local best buy and see if they do that, just for my own curiousity.