Hey, I finally did what many of you suggested and I tried grounding my RCA connectins to eliminate my engine noise. After seeing it work, I need a permanant solution to mounting the ground wire to the RCAs. I would also like to know what guage wire would be best for this application. I would love to see some pics of what people have done.
By the wayim using a pioneer head unit and a jl 4 channel amp for mids an highs.

 

Why not just replace your HU?
all you gotta do is strip the speaker wire as much as you can, wrap it a whole ****load around the RCA shell and ground the other end
or do this

 

wow never seen that done.LOL but then again ive never had that problem either... one thing i do always do tho is ground the radio to the dash frame, the factory wires are never large enough for aftermarket radios.......

 

Im guessing that is a ritoricalquestion giving me another option to solve my problem, but if that is actually a question, its because i dont have $300 just laying around to spend on a new HU.

 

just solder a piece of 18 gauge to the neg housing on your rca line.... iv'e done it many times it works like a champ

 

HERE is a potential 26 reasons to replace your Pioneer with a different manufacturer unit.

 

The one thing that stands out in your description above is "a pioneer deck." Pioneer is known for marginal internal ground planes, and especially for introducing ground differentials (i.e. loops) between front and rear or sub line outputs. Try ensuring a good ground for the HU that is not the OEM wiring harness ground, and try connecting the two outer rings of the RCA cables together.
Another post from the 12volt....from someone that is very qualified

 

Since im running a four channel ampand a single channel ampfor the sub do i need to ground all 6 RCAs.

 

It's a good idea.

 

No you do not. A single RCA will do the job. If you take apart the HU and look at the couplings themselves, you'll notice they are all on the same metal plane, therefore grounding multiple will be no better than grounding one.

And as for your reasons why you can't buy a new HU
son, you can get the top of the line pioneer HU for 200 bucks
it's called direct distribution, instead of getting it online or at a store, call up the company, ask for a list of their closest distributors to your area, then call up the distributor and you're done
I got my pioneer deh-6700ub or w/e the usb one is for 132.43