Ground Noise

Help!!!

I have a 1991 911 and I can't seem to get rid of the ground noise in my system. I moved the ground to a  sanded down spot on the chasis and it didn't help. What could be some of the contributing factors? Thanks 12 volt members for your time.

Drew

Just looking at your signature, it looks like you have a lot of signal processing going on in this car.  Try bypassing one component at a time, and see if that helps.  Also try turning your gains down.  Have you measured ground resistance?

Dear member,

In the past, all I have had to do was move the ground and the noise went away. Can you walk me thru step by step how to measure ground resistance? What tool will I need to purchase? Thanks so much for your time.

Drew

P.S. I changed rca's, and hooked the amps up to the Eclpise head unit and still got the noise.

Dear Supradude,

The eclipse has 3 RCA outputs, that's it. There's no internal amp. I moved the ground for the radio. I think it has something to do with my wires? Is there some set of rca's out there which block ground noise; or are more resistant?

Drew

That's where I started, and the nose was worse! I think I am left with the forgon conclusion of; play it loud and you can't hear it! Thanks for all of your help guys...

Drew

I forgot to mention that I had purchased monster cable's "claimed" rca ground noise eliminating adapter to see if that would help... Couldn't return it fast enough.

The Porsche has the battery in the front trunk. I have the amps and the crossover in this area too. Have I mentioned there is no room in the trunk?

The RCA's are run from the eq under the dash, thru a hole in the firewall, and down the right front fender, but they don't come near any powe wires. The power and ground are run along the front and left of the car's trunk. The remote is fed thru this same hole in the firewall, and is then routed along the cowl area and down the right side. I have a ground and power distribution block on the opposite side of the trunk from rca's.

However the speaker wire does come to same area as the power because the hcca amp has all of its inputs, except rca's, on the side of the amp to where the power is hooked in.

The PPI x-over also has the outputs to each amp on the same side adjacent to the front area where the power distribution is located. The approximate distance would be 8 inches away... What are the best RCA's out there? Maybe the noise is being picked up thru the rca's that are located on the ppi's outputs (front 8 inches away from the power distribution block).

Drew

Drew,

to measure ground resistance, you'll need to get a multimeter.  Set your meter on resistance, and put one probe at the negative battery terminal, and the other at the grounding spot.  In many cases, these don't reach, so use a jumper.  Measure the resistance of your jumper wire first, so you can subtract this from your reading to get your ground resistance.

Dyohn is definitely right.  Ground loops can be tricky in these German cars.  After reading your noisy results from grounding at the battery, I believe you just need to ground your head unit and amp at the same spot.  Do this, and I think your noise will go away.