where do you guys ground your amps in the hatch?

[aktalon]

I am having some troubles with grounding my amp in the hatch. Basically, according to the multimeter, it won't ground to anything except the negative battery terminal. And Im just talking about the power feed, so it doesn't have anything to do with the amp. Its really strange, I have the ground attached right now to a bolt next to the spare tire that says "child safety harness" or something. And I took the paint off too. Whats going on??

Travis

[91TSIAWD_Mark]

I drilled a new hole, sanded off paint, put down a star washer, connedted ground. It reads at 0 Ohms.

[MoBoost]

aktalon : check you negative terminal and grounding wire - they get damaged in time ....

[GermanDSM]

Hi

wouldn't it be better to run a wire (with the same diameter as the positive) straight back to the negative battery terminal??? Thats how my brother and I used to do it...

...just my 0.02DM

[Jeremy-92tsi]

I just ran a wire the same gauge as my power wire back under my back seat and to the seat belt bolt. Really good ground!!!!!

If you really want to run another wire all the way back to the battery through the firewall go ahead. Drilling a new hole or finding a good ground in the hatch would be much easier.

Jeremy

[sab4you]

Originally posted by GermanDSM
Hi

wouldn't it be better to run a wire (with the same diameter as the positive) straight back to the negative battery terminal??? Thats how my brother and I used to do it...

...just my 0.02DM



No thats a bad, bad idea. You want your ground wire to be as short as possible, with least amount of resistance

If there is a surge or problem and your ground wire is all long and resistant, your gonna fry your component.

I used the same place as you, the child safety thing, just scratch off the paint with a flat head screwdriver.

[MoBoost]

The bolts that hold the metal brace in the hatch - I believe that's what I used.

[aktalon]

Ok, I think it might be the cable that connects the negative terminal to the frame. Its kindof hard to see in there thou, do i need to yank the battery out? Where does this cable connect to the frame?

Travis

[GermanDSM]

Originally posted by sab4you


No thats a bad, bad idea. You want your ground wire to be as short as possible, with least amount of resistance

If there is a surge or problem and your ground wire is all long and resistant, your gonna fry your component.

I used the same place as you, the child safety thing, just scratch off the paint with a flat head screwdriver.

I don't think a 20qmm wire could have a higher resistance than your cars body....
just think your cars body is made of steel, the parts are welded or sometimes even glued together...the wire is made of pure copper, one piece!!! I think a copper wire is always the best choice..Not only has copper the superior specific resistance to steel, but you also eliminate the resistance between the car bodys parts (dont know how to call it in english)

Also from a electronic point of view it is recommended to ground everything in one single point. This way you minimize the so called parasitic ground currents. These currents can be heard as a sort of humming noise. (in German you call this wiring method (attention probably bad translation) star-grounding)

just another 0.02DM

[sab4you]

GermanDSM, your statements are pritty much correct electrically speaking, but not good for car audio.

Its silly to state that the car is steel, so a better ground is going to the copper wire. Either way, its going to a steel car. I agree, copper is a better conductor. But the car chassis is ground. The longer your wire to the ground, the worse it is.

Also, agree that a single ground point is the best, especially to keep noise at a minimum. But that doesnt work well in car audio. Its bad practice to have a long ground wire running from battery to your amps in the back - i didnt even think people did it, until I read this post.

A ground wire is where it dumps excess power - you dont want it to be higher resistance than you need - i.e. long wiring.

Talk to any car stereo professional installer (or pick up a car stereo mag), you will NEVER see them run a ground wire to the battery - it will either be a short ground to the trunk, or to a distribution block to consolidate all the amps grounds, then a short wire to the first good ground location.

Edit: I was bored at work, so looked up some references at work for ya:
http://www.ehow.com/eHow/eHow/0,1053,5829,00.html
Step 5: ground is no more than 18 inches

http://www.landfield.com/faqs/car-audio/part1/
section 2.6

No. In almost every case, the best thing to do is to ground your
amplifier to a point that is attached to the chassis of the car and is
as close to the amplifier as possible. The ground wire should not need
to be more than about eighteen inches long, and should be at least as
large as the power wire. The point to which you make your ground
connection should be an unpainted piece of bare metal.


[Edited by sab4you on 02-22-2001 at 06:01 PM]

[GermanDSM]

Its silly to state that the car is steel, so a better ground is going to the copper wire. Either way, its going to a steel car.


Hmm if you run a ground wire from your amps in the trunk to your negative battery terminal...there is no steel of the cars body in the electrical path of the current or am I missing something???


Also, agree that a single ground point is the best, especially to keep noise at a minimum. But that doesnt work well in car audio. Its bad practice to have a long ground wire running from battery to your amps in the back - i didnt even think people did it, until I read this post.

It is really interesting to see how the opinions differ from country to country. (btw I never wanted to play Mr. Wiseguy or disrespect you...just wanted to contribute my opinion from my experiences...)


Talk to any car stereo professional installer (or pick up a car stereo mag), you will NEVER see them run a ground wire to the battery - it will either be a short ground to the trunk, or to a distribution block to consolidate all the amps grounds, then a short wire to the first good ground location.

This is where the funny part starts...round here every car stereo mag and pro installer tells you to run a wire back to your battery! Honestly no BS!!! :-))...maybe they want to sell more copper wire here in Europe! ;-))

[A.D.]

As a part time stereo installer, I've installed many amps in my time, but never once have I ran a ground wire back to the battery. The metal body of your car will be just fine.

The first thing to do is make sure your battery is grounded well, I would upgrade the main ground wire to the frame to at least a 4 gauge. Then make the amplifier's ground wire the same size as it's power wire, NEVER smaller. Ground this wire to a seat bolt, or to a spot that has been cleaned to bare metal. Usually the floorboard will suffice. If for some freak reason it dosn't, drill a big enough hole through the floorboard for your ground wire to fit through and ground the wire straight to the frame. Use a rubber grommet to protect the wire where it passes through the floorboard. I GUARANTEE this will be better than ANY cable run back to the battery. Also, use a star washer in between the ring connector and the bare metal for more bite. You might also consider using a nut and bolt and lockwasher rather than a screw. It will hold a lot better and you won't have to worry about it stripping out later on down the road.

[Grilf]

I grounded my amp to some bolt on the body of the car that I happened to see when I had the carpet pulled up while running the wires...

[Dark Lightning]

I grounded to the base of the hatch shock.

http://www.geocities.com/nmudl/pics/box/

[Orange Crush]

Rear seatbelt bolt here.....

[sab4you]

Also, might as well add in, that wires are nice conductors. They are also nice antenna's (sorry spelling?), so a nice long ground wire would also be picking up more noise.

I dont think its a question of getting the 100% ground to the battery, its a question of safety and where its gonna dump excess power to. A long wire is higher resistance than a short wire. You want excess power out of your component ASAP. If you really need to have it ground directly to the battery, I would suggest moving battery to trunk - alot of car audio competitors do this.

GermanDSM - I didnt think you where being wiseguy :) I enjoy others viewpoints, thats why I participate on these boards.

I aint dissin nobody here, but I would ask your installers if they went to school or got training or certification through anything (such as IASCA http://www.iasca.com/ ). There was a time I was interested in becoming an installer and got the training books for car audio installation. Not to mention studied electrical engineering in college (neither of which mean I am an expert)

I find it crazy that the german installers want to run a ground wire up to the battery, but then I also just found out you guys dont have Ranch dressing either :)

[GermanDSM]

Originally posted by sab4you
Also, might as well add in, that wires are nice conductors. They are also nice antenna's (sorry spelling?), so a nice long ground wire would also be picking up more noise.

I dont think its a question of getting the 100% ground to the battery, its a question of safety and where its gonna dump excess power to. A long wire is higher resistance than a short wire. You want excess power out of your component ASAP. If you really need to have it ground directly to the battery, I would suggest moving battery to trunk - alot of car audio competitors do this.

GermanDSM - I didnt think you where being wiseguy :) I enjoy others viewpoints, thats why I participate on these boards.

I aint dissin nobody here, but I would ask your installers if they went to school or got training or certification through anything (such as IASCA http://www.iasca.com/ ). There was a time I was interested in becoming an installer and got the training books for car audio installation. Not to mention studied electrical engineering in college (neither of which mean I am an expert)

I find it crazy that the german installers want to run a ground wire up to the battery, but then I also just found out you guys dont have Ranch dressing either :)
I guess I found out why they recommend you to run a wire back to the battery....It is mainly because most people running a fat car stereo system don't have enough money to afford a fat (HP) car too. So they buy cheap small cars (Renault Twingo, Opel Corsa/Vectra/Astra, VW Polo/Lupo...etc.) But these cars are also built cheap...parts of the cars body are only point-welded (?) or even only glued (?) together!! This is what I read (in a car stereo mag) as a reason for running a wire back to the battery.

Sorry for the translation...but English is still a foreign language to me...

P.S.: BMWs always have their battery in the trunk...stock!!

[jsegala]

i grounded mine where my power antenna is located, there was a bolt in that compartment under the shield that was un used.

[kevingst]

Let me get an opinion here. I apologize for the length of this. I'm running 2awg power from battery to a distribution block which splits into 8awg for the amps/components. Then I plan to run 4awg groung into a dist. block where that also runs 8awg to the amp/ components. I'm running an Orion XTR 900, Rockford 400a4, and a Rockford EPX2. Should that be safe enough.
Reason I'm concerned is because I took a stupid chance and was using the same power wire without dist block ( not running amp on mids at the time ) going to the amp. And an 8awg gnd wire. The power and ground for the EPX2 ( this is where I got really stupid- and lazy ) came directly from the post on my amp. Suddenly I was getting the piss shocked out of me every time I got out of the car. Next thing I knew, the car was acting funny, the next day it died and didn't start back up. What I found was a gnd that goes from the firewall to the intake manifold. It had melted the insulation off, and was touching a metal sleeve on the thottle cable. It finally touched long enough to blow itself in half and also weld the throttle cable open (btw, a new throttle cable is $38 ). So bascally I know not to do that anymore.

[mavisky]

maybe not the best one out there, but i use the antenna ground. might be why my reception sucks. also keeps the ground wire short. short=good