How to properly make a ground!!!!!

Worlddre
5,000+ posts

Big Darkie
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2
Charlotte, NC
it has come to my attention (from reading various threads on this here forum) that many of the regular members here do not know how to make a proper ground. I there for shall inform the ignorant masses.

This is not going to be a long explanation as it is no at all difficult and for those who struggle with reading comprehension i am sorry there will be no pictures.

What to look for in a good ground

Look for a piece of metal that is apart of the vehicle chassis and not attached to the chassis with bolts or any other methods. For example in the 95-99 Mitsubishi Eclipses there is a little back hump against the back seat that looks like it would be an awesome spot to make a ground and many people and installers :sigh: make this mistake. In actuality this litle piece of metal is bolted to a painted part of the chassis and thus would royally **** as a ground. All in all make sure you are grounding to the unified chassis of the vehicle if not the frame itself. Also you do not need to ground to a factory bolt. While they are convenient if you cannot find one you can simply pick a location (preferably away for rear decks and the like) and attach a self tapping screw to it. Once your grounding location has been selected if you want to be sure you have selected good spot take a meter(DMM) and run a quick wire to the negative post on your battery (doesnt need to be pretty as it will be removed when you're done with it) and measure the resistance. If you can pick up any resistance with a commercially avaiblable meter you have selected a poor ground so try again.

How to prepare your well chosen ground location

This is simple, simply scrape away the paint at your chosen spot. This can be done using a variety of methods. The easiest method ive found is o take a drill and a wire brush attachment and have it until you can almost see yourself. Another method is to take a flat head screwdriver or a utility knife and have at scraping away. This method is not nearly as aesthetically attractive but works nonetheless. The final method is some very coarse grit sandpaper. I personally have never used this method but i cannot imagine it not working for any particular reason

How to prepare you ground wire

This also is very simple. USE A RING TERMINAL. If you do not have any at the time go to walmart or something and get some. They are not going to cost very much so there is no reason not to use one.

How to attach you ground

Also extremely simple. If you chosen ground location is a factory bolt (hopefully you made sure your ring terminal fits around the bolt) simply remove the bolt ,place it through your ring terminal and reattach it to the vehicle. Now if not using a factory bolt then simply inspect both sides of your chosen location. Make sure there are no gas takes or line running under the location you have chosen. Take the shortest available self tapping screw (usually 3/4") and screw it into the vehicle.

In closing this throught process is not only for amplifier installation. I use his thought process everyday when dealing with alarms and anything else i might need to find to ground.

the end

if i neglected anything someone please add it

This post has been promoted to an article
 
I would shy away from using a self tapping screw, since I have had the surrounding metal warp and the screw then becomes loose. I would say using a small nut/bolt combo with some thereadlocker would be the optimum way to go.

 
I would shy away from using a self tapping screw, since I have had the surrounding metal warp and the screw then becomes loose. I would say using a small nut/bolt combo with some thereadlocker would be the optimum way to go.

x2.

unless you are very careful to not over torque the screw, it shouldnt be a problem. i have a self tapper holding the ground in both of the cars.

 
Yeah, but if you're screwing into say, the trunk floor, you don't have access to the other side.

When he says to run a temp wire from the battery neg post and use a dmm to check resistance, how is this done? Battery negative to DMM negative probe and DMM positive probe to the spot you want to ground?

Also I would spray some paint or primer to cover up the bare metal that was exposed so it doesn't rust to **** in 3 days.

 
you should add the dmm method on finding a good ground.
Copied & pasted from another post I made:

Set DMM to resistance (ohms).

You'll need some extra length of wire to reach from where your ground is to the battery.

Now, take one lead of the multimeter (doesn't matter which one) and touch it to the ground location. Take the other lead, use some sort of wire or extended leads, and attach it to the negative battery post. Let us know what reading you get. You should be getting below .5ohms. That's a good starting point. Depending on your wire, you might have some resistivity in there.

Also, make sure you touch the two leads of the multimeter together before testing so that you can see what the resistivity of the DMM itself is. For example, touch them together and you may get .1 ohms. Then, whatever your ground spot reads, take .1 ohms off of it.
 
Copied & pasted from another post I made:
yup thats the dmm method. one problem i am seeing however is the lack of saying that there needs to be no power running through the circuit. which means disconnect the negative terminal from the battery, and use that terminal thats attached to ground wire thats attched to the chassis (lol, thats a weird way of saying it), as your other point to probe too.

when checking resistance in any circuit, you need to power down and isolate. not disconnecting it from power and isolating the circuit will not give you accurate readings.

i also aim for exactly what the dmm reads when touching the leads together. if you get any more, IMHO, you need to use a different ground.

 
I'm a fan of the Gigantic bolt, connecting a gigantic ring terminal to my gigantic (and well sanded) frame.

And then covering with a gigantic coat of underbody coating.

Then from there I do a good job on my grounds up front.

No problems.

 
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Worlddre

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