[Mag]

I have searched the forum about the R/F system getting a popping sound after a new h/u. Many people have said that 7551 is the correct wire harness for the the system because it can avoid double amping. (I don't know how it can avoid double amping because I still had to connect the amp from the new h/u to the aftermarket harness). I tried 7751 anyway, but I still got the popping sound when I change channel or source, and the volume is very low in the rear speakers. I basically connected every wire from the 7751 to the new h/u harness correctly except black/white (the amp ground), blue (power antenna), orange (illumination) because the new h/u does not have these wires.

I know there are many solutions such as bypass the stock amp using 7750, use a Speaker Level Converter or replace the stock amp etc.

The problem is I only want to replace the h/u not the amp, subs or speakers. How can I do that without having the popping sound?

Why doesn't 7751 work for my Pioneer h/u with the R/F system like other people claimed it would?

What exactly causes the speakers to pop when changing source?

Thanks!

 

[i68k]

...but I still got the popping sound when I change channel or source, and the volume is very low in the rear speakers. I basically connected every wire from the 7751 to the new h/u harness correctly except black/white (the amp ground), blue (power antenna), orange (illumination) because the new h/u does not have these wires.

What exactly causes the speakers to pop when changing source?

if youre playing a song and its popping thru the song, you have a bad connection somewhere. if its popping when you switch from say radio to cd player, it could be either bad connection or the head unit itself. a lot of cheaper radios make this popping sound when switching, but it is possible you have something incorrectly wired or double/unamp. i thought the blue wire was the amp turn on wire? what year/model are you working with? i would assume you need the blue & black wires connected to something. how did you connect the wiring? splicing, tapping, soldering, twisting....etc?

 

[Mag]

I'm working with a 02 spec v. I used crimp caps to connet the wires. Does that matter what I used？ where should I connect those unconnected wires？

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[i68k]

im not good at guessing wires, do you have a pic or part# for your harness? i know its 7751, but searching leads me nowhere, do you have brand+full part#?

the black wire def should be grounded to bare metal. the orange illumantion/dimmer wire isnt necessary to hook this one up. however, your blue (power antenna) doesnt sound right, b15s dont have power antennas. i believe the blue wire was the amp turn on. there are wiring diagrams in the fsm that can help you matching colors of the factory wires.

also, crimp caps have a very poor connection and could fall off or let a wire pull out. the best way to do small wiring is by soldering, so you dont lose any voltage or connection. when i wired in my radio, kenwood, it went up to say 26 before it started getting staticy from being too loud, after soldering all the connections, i get way over 30 before it gets staticy.

 

[Y2K SE]

Its actually a Metra 70-7551 harness.

I'm confused. Did you use the head unit's RCA outputs to the Metra harness, speaker (line-level) outputs, both, or some other combination?

 

[Mag]

im not good at guessing wires, do you have a pic or part# for your harness? i know its 7751, but searching leads me nowhere, do you have brand+full part#?

the black wire def should be grounded to bare metal. the orange illumantion/dimmer wire isnt necessary to hook this one up. however, your blue (power antenna) doesnt sound right, b15s dont have power antennas. i believe the blue wire was the amp turn on. there are wiring diagrams in the fsm that can help you matching colors of the factory wires.

also, crimp caps have a very poor connection and could fall off or let a wire pull out. the best way to do small wiring is by soldering, so you dont lose any voltage or connection. when i wired in my radio, kenwood, it went up to say 26 before it started getting staticy from being too loud, after soldering all the connections, i get way over 30 before it gets staticy.

The amp turn on is blue&white. The blue and orange are not used I guess.

I don't know how to do soldering =[

DO you mean both black wires grounded to bare metal? There are two black wires, one from the aftermarket wire harness, one from the h/u harness.

Should I connect the two black wires together, and then ground them to metal? Or ground them separately?

 

[Mag]

Its actually a Metra 70-7551 harness.

I'm confused. Did you use the head unit's RCA outputs to the Metra harness, speaker (line-level) outputs, both, or some other combination?

I did use the RCA outputs. I'm sure everything was connected correctly.

I noticed that when I unplugged the RCAs from the h/u, there was no pop when switching inputs, and of course there was no sound.

what causes the speakers to pop?

 

[Y2K SE]

It generally has to something to do with the head unit. My suggestion would be to ground the head units' harness directly to ground using the shortest length of cable possible instead of connecting it to the ground on the factory harness.

 

[i68k]

x2 ^^^ what he said. always ground your wires to bare metal, and as short as possible. you should learn to solder, audio is a good place to practice your soldering, usually you have plenty of wire to play with. i mean really, soldering iron $10, solder w/flux $5, electrical tape and zipties $5. so for $20 you have the basics to begin soldering, once you get the hang of it, you can move on to other electrical stuff, like o2, maf, tb sensors, etc when they fail or have connection issues.

 

[099ThoStro]

I don't know if the power antennae wire will work for the amp turn on, but it probably does, but it doesn't matter, you can use anything that gets accessory power, I just use the red power lead.

 

[Mag]

I don't know if the power antennae wire will work for the amp turn on, but it probably does, but it doesn't matter, you can use anything that gets accessory power, I just use the red power lead.

No, power antenna is no use. I tried hooking it up to the amp turn on, no sound.

I don't understand your last statement. "you can use anything that gets accessory power, I just use the red power lead.?" What do you mean? Ground the black to red?

 

[i68k]

I don't know if the power antennae wire will work for the amp turn on, but it probably does, but it doesn't matter, you can use anything that gets accessory power, I just use the red power lead.

hes talking about using the red wire for the amp turn on as well, so when you turn on the radio, the amp turns on too. when you use the blue wire, the radio turns on, then the radio turns on the amp when its needed, which is they way it should be. your black ground wires need to be grounded to bare metal

if you use the power antenna(if it was labeled that) for an amp turn on, it will only work when you use the radio, and turn off when you use the cd player. so youll get no amp during cd player, and amp during radio.

 

[Mag]

hes talking about using the red wire for the amp turn on as well, so when you turn on the radio, the amp turns on too. when you use the blue wire, the radio turns on, then the radio turns on the amp when its needed, which is they way it should be. your black ground wires need to be grounded to bare metal

if you use the power antenna(if it was labeled that) for an amp turn on, it will only work when you use the radio, and turn off when you use the cd player. so youll get no amp during cd player, and amp during radio.

Sorry man, I'm a little confused. Are there two solutions?

1. Using the red: Do I connect 2 red and 2 amp turn on (blue and white) wires from both harnesses together, 4 wires together? or just connect the amp turn on from the aftermarket harness to the red wires?

2. Using the blue: There is no blue wire on the h/u, so I don't know what wire connects to the blue. Or do I connect the blue to the red as well?

How do these help eliminate the popping?

If my purpose is to turn on the amp, why do I not just connect both amp turn on wires, like the installation manual? Do you want me to turn on the amp without using the amp turn on wire from the h/u harness? SO I just connect the amp turn on wire from aftermarket harness to the red wires?

 

[Y2K SE]

Despite others' advice, don't use anything but the actual remote-on line for external amps (I believe blue + white stripe). I assume you already have it hooked up this way.

You should still check (and fix) the grounding.

 

[i68k]

you should be using the harness coming from the back of the headunit to turn on your amp. you want your radio to turn the amp on, not have the amp turn on when you put your key in.

the aftermarket harness should be labeled, sometimes there wires different colors on different manufacture harnesses. your headunit harness should have a wire just for the amp turn on. i didnt have any problems when i just swapped out my headunit using the stock rf amp and oem speakers. i remember it was all hardwired without rca for the stock oem rf system. all the wiring is behind the headunit is the factory harnesses.

 

[099ThoStro]

There are no negative effects to the amp turning on when you turn your key, the headunit turns on anyways when you turn the key, it doesn't matter if the headunit or the car turns the amp on. If you wanted you could wire the amp turn on straight into the fusebox. And yes, I meant the amp turn on wire being wired to the red accessory wire not the black grounding wire. The amp turn on can go anywhere that gets accessory power, you could even set up a rocker switch for it, and wire it into your dash. All the amp turn on does is send a power signal to the amp, it does not matter where the signal comes from, well, as long as you don't have it so the amp stays on after you shut the car off lol.

Oh and if this is your first system you are hooking up, just make sure you don't mess up your firewall, it's there for a reason, and don't mount your amplifier to your subwoofer enclosure, after long term exposure to the vibrations, the internal components will be at risk of breaking loose from their contacts. And if you have a sealed enclosure, ( if you have subs ) make sure it's sealed, get a can of fiberglass resisn a tube of hardener and a paintbrush, and coat the entire inside of the box. Wood is naturally porous, so it is not actually "sealed", if you take a strong vacuum, you can suction a piece of paper to the other side of the wood. Try it.
'

 

[Mag]

So basically I wired everything correctly, I matched their functions and colors. But there are three wires black/white (the amp ground), blue (power antenna), orange (illumination) that are not connected to anything. My h/u does not have these wires. I'm sure the wiring is fine.

So you guys think the problem is from the black wire (ground), right?

I have tried connecting the black to different places such as the screw, the metal part of the h/u, and the antenna lead etc, but the pop didnt go away.

I'll try to upload some pics tomorrow when I have time.

When I unplugged the RCAs from the h/u, there was no pop when switching inputs, and of course there was no sound. Does that mean the popping issue is caused by the RCAs?

 

[i68k]

...Oh and if this is your first system you are hooking up....
'

When I unplugged the RCAs from the h/u, there was no pop when switching inputs, and of course there was no sound. Does that mean the popping issue is caused by the RCAs?

ok, i guess i missed something. i thought this was just a headunit install with stock rf system. so you are using your rca to an aftermarket amp, not the headunit & amp harness to the stock rf amp...? there are no rca on the stock rf amp.

edit: yes, the black/white wire should be grounded to bare metal. the framework around the radio&hvac control work for a grounding point once you put in the screws.

 

[099ThoStro]

What I thought he was doing was adding an external amplifier and subs, but he didn't really mention this, I was just assuming, with RCAS to his aftermarket HU and stock rf amp/I don't have experience with the RF amps, so I don't know how to connect the two and not have a popping noise.

 

[i68k]

thats why i got confused for a second, lol. im not familiar with pioneer either. the stock rf amp powers all the speakers in the car if the stock rf amp from the premium package, looks like this one with regular connectors: