i cant figure it out. its perfectly clear when the key is in II but when i put it in III (without starting the car) i get some interference in the components. i have changed grounds and re ran the power wire. also tried ground loop isolators. any suggestions? here is the setup:
Pioneer Premier 780mp Head unit
MTX Sledgehmammer Enclosure t7512-44 subs
MTX Thunder Elite Amp 801D
MTX Thunder Elite Amp 404
MTX Components
MTX Coaxials
NipponDenso High Output Alternator
StreetWires Zn2 Rca's
Tsunami 2 Farad Capacitor
Tsunami 4 Channel RCA's
Tsunami Battery Terminals

 

Where did you ground the amps? And have you tried to ground the HU directly to the chassis?

 

i have the head unit grounded directly. the amps are grounded at the rear where the old seat belts were. i sanded the area down before i grounded it out. as you can see the battery is grounded twice as well

 

I have heard of a few people have the problem that you are having and it ended up being the actual HU. Have you tried to run a new set of rca's from the radio to the amps? Are the RCA's & power cable routed on oppsite sides of the car?

 

havent changed the rca's yet, but they are the top of the line tsunami ones at circuit city. its just weird that i have no noise at II. and its not engine noise because the car isnt even started. i have moved the power and ground wires on the amp. no help. i guess rca's is next...

 

oh and it only does it on the front components. the rear coaxials are not on the amp and they have no static. so obviously its something to do with the amp. i changed the speaker wire going to the components, didnt help

 

if the gain is up too loud that can happen as well. Remember gain is not a volume control, it is an input level adjustment. Adjust the gain according to the output voltage of the HU.

 

yeah the gain is only at 1/4. i know what the gain is. lol

 

So sad, another Pioneer HU with noise when connected to other then a Pioneer amp.
I would also try another set of RCAs, just run them over the seats and carpet to the amp to try it, if it makes no diff. you will know it's not the RCAs.

I would also try this...
Connect HUs ground to the stock radio harness ground.

Ground the chassis of the HU to the cars chassis using a metal "L" bracket from the back of the HU to the stock metal back support.

When you attach the "L" bracket to the back of the HU also add a "dump ground lead", 16ga wire, on a ring terminal, long enough to reach the amp, again run it over the seats and carpet to the amps to test, turn system on, [III] then touch the bare end of the wire to the chassis of the amp, [chassis screw], one of 3 things will happen...
1- nothing.
2- the noise gets worse.
3- the noise goes away.

I generally run a dump ground when mixing brands and always when the HU is a Pioneer.

Another thing to try, if not already so, ground both amps to the same point.
BTW how long are the amps ground cables?

Not so weird that you have noise when ign. is on run, [III] and not on acc., [II] many more things are on when the ign. is in run position.

I am looking at the pix and I can only make out one set of RCAs running from the HU but there are two sets, "Tsunami 4 Channel RCA's
" in the 4ch amp and obviously one set in the sub amp, and you are not using the 4ch amps summed output for the sub amp....

How many sets of RCA lead are running from the HU?
Where and how are they routed to the amps?

You say only the front speakers are amped, yet it does not look like the amp is bridged, [speaker leads from front outputs only] but both front and rear RCA inputs are used??????
What's the deal? 94

 

yeah i planned to hook up the rear speakers on the amp too, but never got around to it. so i have the 4 channel rca's plugged into the amp. the amp has a switch for 4 channel or 2 channel operation. i have a different set of rca's going to the amp for the sub. ill try the grounding stuff tomorrow.

 

swapped the rca's and the noise at III went away, but once i started the car i have alternator whine now. one thing after another...