JazzRox

Hi,
I'm installing an aftermarket Radio into my '90 vert. I've searched & found that the "whining noise" I get in the speakers is likely the result of "bad Ground". I've tried back, forward, even the dreaded "cigarette lighter" ground...no joy, whine, whine, whine.

While fiddling about, I accidentally disconnected the ground while the stereo was playing, and ....<silence>...no whine. I'm so friggin' frustrated that (altough it goes against everything I've read, God, and country) I'm wondering if I can go without the ground? What are the consequences of this?

By the way....those of you nay-sayers that told me the stock head unit was crap & should be the first thing replaced & would make the biggest difference (budget notwithstanding) were 100% CORRECT. Just thought I'd throw that in....

Thanks all

Scott 89t2

umm.... it won't work without the ground. you sure you got the right wire??....

JazzRox

Yah....Thats what I thought too. I'm positive that this is supposed to be "attached to a metal surface of the car" <from the installation guide>.
It must say 10 times "be sure to connect the black wire to chassis before you ....."
Very strange.

JazzRox

More clues :

-I bought a wiring harness adapter, I thought it peculiar that it had no "ground".

-I did a continuity check from the deck's ground wire (unattached) to the chassis with only the harness plugged in....Positive continuity.

-I did a continuity check from the amps (ganged grounds) to the chassis.......Positive continuity.

I think one of the amp housings is touching the chassis.


Hmmm...

JazzRox

It appears the "dimmer" has continuity with the chassis. Is it possible that this is providing ground, and is it "enough" ground to accomplish whatever "grounding" is supposed to accomplish?

I apologize for the electronic ineptness...ths thread must sound pretty silly.

Icemark

No, you more than likely are grounding through the antenna.

If you were grounding through the dimmer circuit you can burn out your dimmer control for the lights.

The factory radio grounds through the lower two screws in the factory mounting brackets, most people do not retain those brackets when installing the aftermarket radio, therefore it is recommended to ground to the bolt behind the lower access panels on the center consol. That keeps the ground on the same ground plain as the factory ground.

Bambam7

I need a few more details... what kind of whine, does it go up and down with the engine revs, do you have an MSD ignition... what amps, what setups, etc.

First, you must determine the path of entry for the noise. This is what's causing the whining.
Play with the volume on the head unit and the amps (you mentioned you had amps..). If the whine volume goes up when you increase the amp volume, but not with the head unit volume, then your problem is a noisy power source for the amp, or noise on the input cables.
You can get noise isolators for the input cables (called ground loop isolators) and also for the power. (These are noise eleminators available at Walmart even...)
The ground loop noise is induced when the different components of the radio see slightly different potential from the grounds. Try to ground everything as closely as possible if you have this problem, and make sure they are all good grounds.

Try grounding the radio directly to the battery, or where the amp is grounded.

twinrotorTII

groung the radio to one of the 4 bolts around the shifter, I did that no whine n I got 12oo crunch amp. Also when I took out the previous radio(aftermarket tho) there was a weird box to counter the rotary motor it makes weird electric problems from what i hear, but i didn't use the box and no problem

JazzRox

Ice,
The antenna wasn't attached, the only other wire (besides 12v continuous & remote amp on) was the dimmer. By the way, the relay i bought for the backup light fix (that didn't work account zero juice in the switch line) is now employed turning on the factory antenna. Cool. :-)

Bam,
Looks like its the ground from the deck making the noise, it changes freq with the rev of the engine. Pyramid 240 for the fronts, Jensen 150 for the subs, Orkan 180 mini for the driver headrest. (No amp for the passenger headrest yet...trying stuff out first)

Twin,
The top left bolt at the shifter was my first attempt.

Here's the wacky part...I'm grounding somewhere because I have continuity to the chassis from the unconected grounds of the amps( ganged) and the deck. It couldn't be the bottom screws of the bracket because the unit is sitting on the passenger seat. During experiments I took power & ground direct from the battery...better, stil noisy.

I'm about to break-down & get the noise supressor for the power/ground.

Thanks a ton for the input.

JazzRox

Oh...Bam, I don't know what an MSD ignition is.

Icemark

Too many off brand components... ground loop for sure.

If the RCA cable was hooked up to an amp, then you were grounding through that. Bad ground bad bad ground.

You have ground loops, you need to ground everything to the same spot, (and not the shifter... the paint was applid to the screw hole before the bolts went in, it is a poor spot again move it to the side of the consol. behing that screw on panel at the consol frame bolt) and probably will need ground loop isolator if your dead set on using so many different brands/amp types.

JazzRox

k, thanx. That ought to keep me busy for awhile.