800PRS/Grounding Issue

[jrwalte 10+ year member]

This has me stumped. I cannot resolve an alternator whine coming through my 800PRS. In addition, I get a noise when the key is at the 'ON' position but not while it is in AAC (or whatever it's called).

I had what I believed to be a PICO issue. I returned the HU and got a new one. It worked, but I still had a barely audible alternator whine (no whine when in the ON position). However, after about 4 days, while driving down the road - BOOM - loud alt whine begins and noise exists when in the 'ON' position.

Tests:

1) I tested the amps at the amp and from the RCAs at the HU with my PSP. Both are clean. Both amps are grounded through a distro block to o guage and then a street wires grounding block. The only thing I noticed from the RCAs at the HU is when I had only the sub hooked up and the front RCAs hanging loose I'd faintly hear the music in my fronts even though they weren't connected if I turned it up. When I'd only have the fronts connected there would be no noise. Does this mean something?

Another thing I noticed is I would get noise when the RCA plug to the PSP was disconnected but it would go away once I connected it. I suspect this is just due to an 'open ended' rca cable?

2) I ran a dedicated 10 guage ground and hot wire from the battery to the head unit. It didn't help at all. I also made sure the harnesses were on the far left side behind the HU and the RCAs on the right.

3) I connected a friend's Kenwood and I have no alternator or 'ON' noise. His did have a CD player noise on the sub amp if you turned the gain way up, though.

Do I just need to trade in this Pioneer and get an Alpine or something else?

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[jaredspl 10+ year member]

ground the rca's on the head unit

 

[dman4486 5,000+ posts]

you need to fix the ground before repairing the hu......don't use the factory hu ground

run a dedicated ground for the pioneer, and make sure the chassis is grounded as well as the harness....then fix the hu or get it replaced

 

[jrwalte 10+ year member]

I don't like grounding the RCAs because it is just a 'band-aid'. It didn't completely get rid of the noise and it sounds as if it lowers the quality of the audio coming through.

Dman,

I have a dedicated power and ground wire coming from the battery (this is after the 2nd PICO blew). Chassis as well as the harness? Are you saying I should Y split the grounding wire and connect it to the black pioneer harness wire and to a screw on the chassis of the HU? Or should I run two dedicated ground wires to the battery?

Also, I assume this extra ground won't help anything until the unit is replaced and the PICO issue resolved?

 

[bigbangtheory 5,000+ posts]

Just kinda fixed my altenator whine on my 880 PRS yesterday. Friend says I have bad RCA's, both of them! He took a dedicated wire and strapped it to a screw with a bolt to the back of the radio and then wrapped it around the RCA's, so I guess that would be grounding the RCA's right? Almost all the whine is gone. Very faint to where I have to listen real good for it. Before hand it was to the point I was ready to sell my system, so I am happy..............even if it is a band aid fix.

 

[dman4486 5,000+ posts]

I don't like grounding the RCAs because it is just a 'band-aid'. It didn't completely get rid of the noise and it sounds as if it lowers the quality of the audio coming through.
Dman,

I have a dedicated power and ground wire coming from the battery (this is after the 2nd PICO blew). Chassis as well as the harness? Are you saying I should Y split the grounding wire and connect it to the black pioneer harness wire and to a screw on the chassis of the HU? Or should I run two dedicated ground wires to the battery?

Also, I assume this extra ground won't help anything until the unit is replaced and the PICO issue resolved?

not two dedicated grounds, just the one and split to the chassis..there would be no difference unless you did the below or replaced the unit.....also get some higher quality rca's if you haven't already

Just kinda fixed my altenator whine on my 880 PRS yesterday. Friend says I have bad RCA's, both of them! He took a dedicated wire and strapped it to a screw with a bolt to the back of the radio and then wrapped it around the RCA's, so I guess that would be grounding the RCA's right? Almost all the whine is gone. Very faint to where I have to listen real good for it. Before hand it was to the point I was ready to sell my system, so I am happy..............even if it is a band aid fix.

it is not a band aid....the hu grounds the rca's, but has a fuse....you grounding them separately is the same thing!! if you want a more in depth fix, open the unit and replace the pico with another pico or a resistor....I replaced the pico with a wire to ground on the board in my 7500mp

 

[jrwalte 10+ year member]

not two dedicated grounds, just the one and split to the chassis..there would be no difference unless you did the below or replaced the unit.....also get some higher quality rca's if you haven't already

I have the Monster 300 series for my fronts and 400 series for the sub. Are they not of sufficient quality?

 

[dman4486 5,000+ posts]

I have the Monster 300 series for my fronts and 400 series for the sub. Are they not of sufficient quality?

should be good

 

[jrwalte 10+ year member]

I've noticed something else now (still don't have a new HU yet). I've been driving around with my MP3 player y adapted into the RCAs for the front and sub. No noise like I originally stated. But if I have the cable disconnected from the MP3 player I'll have loud alternator noise (granted the gains are turned up to make up for the low volt preout of the MP3).

Does this mean I have a bad ground at my amps or am I just getting noise because I have an open end on the RCAs?