Suggestions on what to try next to get rid of alternator whine?

[dubster]

Hi Guys

Typical question

Ok, I've established that it's not the amp. If I run an ipod through the amps rca inputs when the engine is on - no problem.

I've made sure the head unit and amps earth use 4 gauge wire to the same hole in the chassis with the paint taken off it.

I've earthed the rca leads coming from the head unit.

I've tried different rca leads.

Theres no power lead near the rca leads.

I think Im gonna try a ground loop isolator later on today.

Someone else suggested an anti-noise capacitor after the alternator ?

I noticed in the sticky that maybe I should earth the RCA to the chassis of the head unit rather than the car body - would this make much difference?

Any other ideas folks?

Thanks!

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[loopkiller 10+ year member]

Long shot here, but is the antenna grounded well? When you connected the iPod to the amp, did you use the RCA ends that plug into the HU? Or did you use a different set of RCAs?

 

[ngsm13 5,000+ posts]

Pioneer HU?

nG

 

[loopkiller 10+ year member]

Pioneer HU?
nG

He said he grounded the RCAs. That takes care of the Pioneer issue.

 

[DidUHearThat? 10+ year member]

You have a 4 gauge power and ground to your H/U? I thought my 8 gauge to H/U was silly and hard to work with.

Try this:

Ground the H/U directly to the chassis within 18" of the H/U.

Move the RCA away from power wire and other electrical in the car.

Do not loop spare/slack rca cables. If you need to, figure 8 coil them away from electrical and power.

Check to make sure your alternator is properly grounded.

If all that fails, you can upgrade to shielded rca's (but it may not help much).

Or you can run speaker level output from the H/U to the amp and use a LOC at the amp. Speaker level wires are not as sucepetable to RF noise as rca/line level.

 

[audiolife 5,000+ posts]

This might sound crazy but check your spark plug wires

 

[dubster]

Long shot here, but is the antenna grounded well? When you connected the iPod to the amp, did you use the RCA ends that plug into the HU? Or did you use a different set of RCAs?

Disconnected the antenna.

Different RCA leads from the ipod, but have tried various sets included shielded ones which all made no difference.

 

[dubster]

You have a 4 gauge power and ground to your H/U? I thought my 8 gauge to H/U was silly and hard to work with.

Ground the H/U directly to the chassis within 18" of the H/U.

Move the RCA away from power wire and other electrical in the car.

Do not loop spare/slack rca cables. If you need to, figure 8 coil them away from electrical and power.

If all that fails, you can upgrade to shielded rca's (but it may not help much).

All of that is the case.

Check to make sure your alternator is properly grounded.

Or you can run speaker level output from the H/U to the amp and use a LOC at the amp. Speaker level wires are not as sucepetable to RF noise as rca/line level.

Cool, I'll add those to the list of things to try when I have another go tmrw.

ta

 

[dubster]

This might sound crazy but check your spark plug wires

Ok, ta, will do!

 

[Sanchito 10+ year member]

earthed?

yeu mean grounded?

 

[audiolife 5,000+ posts]

Ok, ta, will do!

I had a buddy with a tape deck with one of those cd adapters to hook a walkman up to it. when he played cds he had engine whine. 4 months later he tuned his car up (replacing the spark plug wires) the noise was gone