Before you send back your headunit, or externally ground the RCA shields, you should
use a multimeter (on ohms, to measure resistence) to check to see whether the RCAs are
grounded properly or not. Don't try to fix a problem until you know it is a problem.
Unplug the RCA from your amp, leaving the other end connected to your headunit, and
check the resistance between the outer (shield) connector and a known good ground.
If the resistance is low (< 1 ohm), as it should be, that's not your problem.

 

I did something similar, if not equal.

What I did was test all of the RCA's I have by checking continuity on the outer shall - ground to ground and then again using the center prong - signal to signal. All of the RCA's checked out fine during this test.

That's when I tested the outer shell of the RCA Pre-Outs on the head unit, and discovered they were not grounded to the head unit.

I believe these two tests conclude that the head unit is at fault.

-Greg

 

yes, if you've tested the pre-outs themselves, then you know they're not grounded.

 

And I do!

 

Thank you 2big4aS2000! I agree! This is a commonly missed step when upgrading your system. You chassis is one huge resistor. Your ground should always be upgraded. Most people think current flows + to - but in truth if flows from - to +.

Its like sucking a milkshake through a large straw that reduces to a small straw. It will flow but not very well. Now increase the size of the small straw to the same size or lager and it will flow much easier.

 

I'm on board with you guys and your milkshake analogies. I believe I have enough 4 gauge wire to redo some grounds and I bought some nice copper ends for the mounting points. - Hopefully they won't corrode? Now that I think about it perhaps I should have gotten aluminum.

Anyway, I had my kenwood deck repaired. The ground in the head unit was 100% my problem. After that was fixed, popped in the new deck and viola- distortion free!

Cheers,

-Greg

 

Glad you got it figured out WarTowels!

I had a hell of a time trying to figure out the ground loop that existed in my 2005 Ford Focus. it seemed to come and go as it pleased. All grounds were checked, all RCA cables were verified good, head unit was well grounded and verified to work fine by swapping with a known-good head unit, I tried everything in the book and never figured out what it was.

When I hooked up 2 amps in my S2K, I was deathly worried I would have another ground loop.

Ground loops are the devil!

 

Oh yeah man, I had to rip my system apart. Took me two weeks to solve this as I had a mini vacation in the middle of it. It was super frustrating.

But I'm quite pleased it's all working now!

Woot.

-Towels