pioneer HU ipod/cd different noises

[andrewk]

Hey all,

Got a bit of a prob, have read and tried the sticky at the top of forum but no luck.

Pioneer HU running 2 speakers off an amp.

HU had power direct from battery with fuse and is grounded up front.

Amp is in the back also grounded and RCA and power wires are on opposite sides of the car.

HU has pc-1200(?) ipod adapter plugs into one small special plug on back for full ipod control...

When car is on ACC i can hear the cd player spinning/changing tracks etc and slight hiss. If i switch source to ipod the hiss goes and sounds sweet as!

When car is running with cd player on still hiss and can hear spinning etc BUT when on ipod can now hear a whining? engine i'm guessing?

Thing is this whining is only when using the ipod...doesn't get louder and only noticable at low volumes. The hiss with the cd player is only a little bit but you can hear it at low volumes.

Any ideas? I read on here about running another short ground from battery to clean metal? don't think thats my prob tho.

cheers

-andrew

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[loopkiller 10+ year member]

What kind of car is this? Where do you have the amp grounded? If you disconnect the battery power, then remove the RCAs from the amp inputs, does the hiss and noise go away? I know there will be no music. If so, the issue is at the HU. You might want to run a dedicated ground for the HU. You can also search the forums and look for a post about how to ground the RCA outputs on the back of your HU.

 

[andrewk]

ive grounded the rca outs on my HU still get an engine whine...thing is it doesn't get louder with volume or rpm...can only notice it a low to mid volume...its annoying. HU is grounded to clean metal on passenger side. I ran another ground from back of HU screw to another point still the same...I know its the HU because when disconnecting the RCAs it goes away.

edit* could it be that my factory ground from my batt - is insufficient? sorry new to all this car electronic stuff. The places where I have grounded are all part of the body but are clean and sanded...amp is like this works fine but HU is causing the prob.