# Question about headunit grounding!



## Truconcept (Jan 7, 2013)

Hi,
Im running an Alpine 2v headunit
Im not very confident in the 1999 factory radio ground 
so with my upcoming build, I want to redo the ground to the headunit

Ive heard the best way to do this is running 8gauge 
straight from the battery to the headunit
*
Would this be the best way to prevent a loop?*
I would only run the ground to the negative on the batt
I would leave the positive connected to the factory wiring


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## jhsellers (Jan 7, 2012)

I think it's more important that you provide the head unit with the same ground reference that the amplifiers have. I run a #14 or #12 AWG copper (from the HU chassis) with my remote wire and RCA interconnects to the amplifier, then connect this to the same ground point to which the amplifier is grounded. 

You can leave the factory HU ground(s) in place. 

Hope this helps,
John


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## Notloudenuf (Sep 14, 2008)

I would ground the head unit to the chassis just like you would ground your amp to the chassis. Find a piece of the body or steel framing for the dash behind the head unit and ground your head unit to that.


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## cruzinbill (Jul 15, 2011)

I will agree with what notloudenuf said. thats really all you need to do. But I would just check the factory ground for resistance first. If it looks good then leave it be. 

If you just wanna redo it for the OCD in your head then find a grounding spot, drill a hole and stick in a bolt with a nut. Then put a terminal on the ground stick it on the post and throw on another nut. Wheres that wire gonna go then? F'n Nowhere!


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## ATOMICTECH62 (Jan 24, 2009)

Do you have a problem with the ground now?
Finding a good solid ground point in the dash should be fine.
In my 50years I have never had to go to that extreme.


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## goodstuff (Jan 9, 2008)

Truconcept said:


> Hi,
> Im running an Alpine 2v headunit
> Im not very confident in the 1999 factory radio ground
> so with my upcoming build, I want to redo the ground to the headunit
> ...


I would try to ground to the frame somewhere if you don't trust the factory wiring. Then if you have issues run your ground back to the battery. No need to waste time and money if there is no problem. 
There is nothing wrong with doing it that way, it's just overkill.


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## cruzinbill (Jul 15, 2011)

ATOMICTECH62 said:


> Do you have a problem with the ground now?
> Finding a good solid ground point in the dash should be fine.
> In my 50years I have never had to go to that extreme.


good god man did you crawl from the womb with an amp kit in hand lol


I wanted to add, what kind of car is it? Also, did the previous person hack the wiring up or anything?


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## Truconcept (Jan 7, 2013)

1999 oldsmobile alero
and the wire is brittle
i have times when my headunit restarts at high volume
im guessing this is from the ground not being able 2 handle the 2v preamp output 
at full tilt


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## ATOMICTECH62 (Jan 24, 2009)

cruzinbill said:


> good god man did you crawl from the womb with an amp kit in hand lol
> 
> 
> I wanted to add, what kind of car is it? Also, did the previous person hack the wiring up or anything?


Well,40 years.Started helping dad in the early 70's with 8 tracks,CB's,linears, speakers,and those FM adapters to get FM on an AM radio.Any one remember those?
And the in dash CB/cassette decks.


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## cruzinbill (Jul 15, 2011)

Truconcept said:


> 1999 oldsmobile alero
> and the wire is brittle
> i have times when my headunit restarts at high volume
> im guessing this is from the ground not being able 2 handle the 2v preamp output
> at full tilt


possible buy not likely. What headunit do you have? I think its more plausible that if you have a large amp and the stock battery/alt, once you are hitting that large current load its just dropping off. Ive seen it before in an old car I had that had a ****ty battery. 

I would say take a look at your electrical system to see if its all up to snuff. Im not sayin go throw in a bunch of new stuff. Just make sure its all good. 

Also ive seen some lower end radios turn off from being maxed out from over heating and such.


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## scooter99 (Dec 21, 2008)

I would say giving us the head unit model number is a good start. 

I had an Alpine CDA9886 recently and found that at higher volumes it would restart on occasion. I was using my phone on a 3.5 mm adapter at that point and figured out there was an issue because I had a case on my phone, the adapter wasn't seating all the way in the phone so it was causing a short of some sort. It would not restart on high volume on the radio, but only when the phone was plugged in. When I figured this out, I removed my case, plugged it back in and ever had a problem again. 

So it may not be your ground at all. But grounding to the frame at any point should do it. 

If you say your ground wire is brittle, I'd say cut it back to a point where it's not brittle and solder or butt connector on a new wire. If it's the wire to the car, not the head unit, that's brittle, ground to the frame and don't use the stock wire. 

Hope that helps.


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## kustomkaraudio (Jun 20, 2009)

jhsellers said:


> I think it's more important that you provide the head unit with the same ground reference that the amplifiers have. I run a #14 or #12 AWG copper (from the HU chassis) with my remote wire and RCA interconnects to the amplifier, then connect this to the same ground point to which the amplifier is grounded.
> 
> You can leave the factory HU ground(s) in place.
> 
> ...


yep... X2 great way to do it.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Theres nothing in the handbook saying you HAVE to use the factory harness to power the HU, constant power from the battery, ground from anywhere.. switched power means little here

Sent from Hell (Tapatalk)


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## Vital (Feb 23, 2010)

How would one check for that "absolute perfect" ground location with multimeter?
I can get that fancy meter that I know works magic lol but I have no idea how to use it


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

..... phone phale


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Vital said:


> How would one check for that "absolute perfect" ground location with multimeter?
> I can get that fancy meter that I know works magic lol but I have no idea how to use it


Read the manual 

And theres no such thing as "perfect" not in the world I live in at least

Sent from Hell (Tapatalk)


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## Truconcept (Jan 7, 2013)

no such thing as a perfect ground in a vehicle, it moves


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