Please forgive my laymens terms and length of the post:

On a radio (pioneer) when you turn the "Sub Off" does it remove the signal from the RCA cables only?

Does the amp still send "power" to the wires but not "sound"?

I have a 5 channel amp in the trunk 4 speakers, 1 sub output.......

At the drag strip I removed the sub and turned off the sub on output on the receiver, left the wires sitting in the trunk.

Last night with what I thought was the radio off.....(it might have been just turned all the way down) The sub speaker wires from the amp slid over, contacted each other and metal in the trunk.

I got the most horrendous full volume "signal noise" from the rest of the speakers.......not high pitch but loud as heck......I grabbed the radio as fast as possible and tried to turn it down and off while driving but I don't know if it was really on radio, CD, Ipod or off?

I seperated the wires from each other and secured them away from the metal...

MY PROBLEM: Now I have the most annoying rpm and volume dependent whine coming from the speakers.....What could have been damaged to cause the whine? It is similar to when there is a bad gound.?

The stereo has been in the car for over 2 years with no issues, so I would assume it has been grounded fine until last night.

The twist: I was at about 6000 RPM in 4th at the dragstrip when this happened.......I would assume it is directly related to the wires on metal but I wouldn't rule out another issue.....say if a ground on my egine came loose?????

Any thoughts on what I should look for or where to start looking for this Whine noise?

Thanks,
Matt

 

Check power and ground connections and ensure they are still tight and secure. Unplug the Rca's from the amp and check to see if the noise still persists. If so, you have an amp ground problem or internal amp problem. If not, next: I would go to RadioShack and pick up a 3.5mm to RCA adapter(6 bucks), connect it directly from the ipod headphone output to the amp rca input. If you still get noise or popping when you switch tracks, the amp is definitely hurting. If you don't have any noise at this point, your headunit could have issues. Check all connections behind the radio and ensure they are solid. Where did you ground your radio? You can also perform this step before you buy the adapter. Many Pioneer stereos have been absolutely notorious for alternator whine, hiss, popping, and general noise.

Does the sub output still work?

Goodluck.

 

To answer your first two questions, yes and yes.

 

Great, thanks for the reply....I left the radio off for the drive home, got home late and parked it. I will checking it over tonight after work.

I did the install about 2 years ago (myself).....I believe the ground for the radio is to the metal floor behind the center console in front of the shifter.......

Thanks for the help, I'll let you know what I find.
Matt

 

here is the answer:
pioneer decks have a really crappy fuse setup inside the headunit and when you disconnect RCA cables while the HU is on, or LEAVE THEM DANGLING (or both) you break that fuse and create the noise.

this is what you MUST DO NOW.

you have them wrap around the rca terms to give them a solid ground.
looks crappy but the other option is getting the deck internal fuse replaced

 

Update:

The amp appears to be working just fine....I purchased the adapter to plug my IPOD straight into the amp and there is no noise when the music is sourced from the IPOD.

It appears to be in the head unit as stated above.....I can't do the fix like picture because my radio has 3" long pigtails for the 3 RCA outputs (FR/RR/sub)........

How hard is it to replace the internal fuse......more importantly what kind of fuse is it if I open the case? Is it soldered into place?

Thanks,
Matt

 

I have a 800PRS and was lucky enough not to have the "notorious" ground issue. Copper case and two grounds and I have no noise ever!! Thank gosh.

 

You will have to take the headunit apart. All the screws should be readily visible, including the screws behind the face plate. You may have to remove the cd drive from the headunit, but I don't know for sure. It should also be a set of relatively easy to get to screws and probably a ribbon cable or two. You should be able to see a fuse inside and it should have the size stamped on one of the ends.

You may try running a small ground wire (the same size as your remote turn on wire will work) from the casing of the head unit to the casing of the amplifier. I have seen instances where this works, but it may not. You could also solder a wire to the outside connection to your rca cables (really easy if you have the type where you can unscrew the connector) and ground it which is the same thing as above.

Then again you might just want to take it in. Hopefully it's still under warranty. I wouldn't tell them what happened though.

 

Thanks guys.....I found more info on line regarding this issues with Pioneers.....It appears to be very common because oif the PISO fuse they use.

When I get around to fixing it I will update the post again.

Thanks for the help/direction,
Matt

 

the fuse in the pioneer is NOT a typical blade or tube fuse you find at a hardware store- you would have to have someone solder in a replacement.

to the OP i know you have pigtails as my 880prs did too- all you have to do it wrap wire around the ends of the rca plugs, then plug in your RCAS that go into your amp- they will "clamp" the ground wires you put there, then ground it to the deck chassis.

 

Awesome Pioneer info in here. All excellent posts. I was eventually going to get around to grounding the Rca's after he got back to us about the radio being the issue. In the past, I have used solder and the metal leads from a resistor to accomplish what is done with the copper wires in the picture above. It looks a little neater and frees up a little more space. Goodluck Dropspeed!

 

I see. Thanks. This is the cause of the ground noise issue that Pioneer's have had for the last couple years? Wow.

 

UPDATE: I ran a ground wire to (around) all of my RCA outputs and grounded them to the chassis of the car.......

THE NOISE IS GONE!........I might take the radio apart one day and try to fix the fuse but this worked as noted above.

Thanks for all of the help!!!

MATT