Amps buzzing and popping

[NICKYPOO]

Two amps, head unit, remote and ipod interface all running off of one battery. One stinger 200 amp isolator. Once I turn the battery on either ACC or ON there is a horrible buzz coming through the tower speakers (amp #1) and I suspect it would be there on the sub (amp #2) but you can't hear anything until you turn the key off and then both amps put out a single "pop". Turning the volume down does not help. I didn't have this problem until I hooked up the isolator. Why just the amps? The speakers running off of the head unit are unaffected. Would a distribution block help me out? Is the isolator hooked up wrong? The turn on wire is linked to the ACC power to the deck. The ground is running to battery #2 (all stereo).

[dogbert]

I still think you have an issue where you're building up voltage between components on different circuits (i.e., not on a common ground). Popping is bad...you can fry your components pretty quickly if it's not fixed.

Does it make the same sound as when you plug a microphone that's on into an amplifier (like a guitar amp) that's on?

[NICKYPOO]

Originally posted by tweirich
I still think you have an issue where you're building up voltage between components on different circuits (i.e., not on a common ground). Popping is bad...you can fry your components pretty quickly if it's not fixed.

Does it make the same sound as when you plug a microphone that's on into an amplifier (like a guitar amp) that's on?

I think you're right and yes to the guitar amp question. The thing is, the head unit, amps and isolator are all on the same power and ground (battery 2). I have yet to try and hook the isolator up with the RCAs being grounded to the HU chassis.

[dogbert]

Is your head unit wired to the ACC switch on your dash? If so, you may want to check how that switch is wired. If it's getting power from another source or grounded to a different circuit, that could be an explanation. Without seeing a complete wiring diagram with and without your switch, I can't really make any good suggestions.

[NICKYPOO]

That's exactly how how it's wired. So lemme get this straight, I need to run a new ACC switch wire direct from the key but do I need to run some sort of ground for it? Because the ACC wire that the head unit is on, is wired through a circuit breaker on the dash which is grounded to the factory ground block. Would that account for the delay of the head unit switching off before the amps thereby "leaving signal in the lines" to the amps? Hmmmmmmmm.

I really appreciate your help on this one dude. It's the largest stereo project I've ever tackled and wiring is my "achilles heal". Beers are on me.

[dogbert]

Ok, here's the problem you have. You know how your ignition switch cuts out your head unit while you're starting the boat? When this happens, the isolator will be switching how your circuit runs. My recommendation you do one of the following:

1. Completely isolate your ACC switch onto the 2nd battery (the one for the stereo). This means that all of your accessories will be on that circuit. This way you can have a common ground for everything. You'll need to find out if anything else is controlled by this switch and make sure those accessories are grounded to the same circuit as well.

2. Remove your head unit from the ACC switch and wire it and all the amps directly to the 2nd battery. Ground them the same way. The downside here is that you lose the ability to turn off your stereo from the dash.

I know it sounds like a pain in the butt, but that's what you're going to have to do. If you don't, you will ruin your speakers in pretty short order. Hope this helps.

[NICKYPOO]

It's all becoming clear now. Thanks Dood. All I really need to do is cut the ACC lead going to the head unit. I just need to remember to turn the stereo off from the remote on the dash every time I get out of the boat. That should be the toughest part. Shouldn't I be able to use that same ACC wire for the isolator? If so, can I ground it to Battery 1? That would put the entire charging and ACC system on battery 1 and on a complete cicuit leaving just the stereo on battery 2 within it's own circuit. Is that right?

[dogbert]

Originally posted by NICKYPOO
Shouldn't I be able to use that same ACC wire for the isolator? If so, can I ground it to Battery 1? That would put the entire charging and ACC system on battery 1 and on a complete cicuit leaving just the stereo on battery 2 within it's own circuit. Is that right?

Not sure I understand what you're asking, but the main thing is you want to eliminate the connection that's going to your ignition and make that go directly to battery 2 instead (assuming battery 2 is where your stereo equipment is). You may also need to run a seperate ground from the ACC switch back to battery 2. That way you have that whole circuit isolated to battery 2 with no chance of feedback. The more I think about it, that may be the easiest way to go, but I haven't really looked at the wiring on my switches to know. I will be heading to my lakehouse tomorrow and will try and remember to look under the dash. I'll let you know what I find and report back.

I think I'll stick with my PERKO switch for now. I don't mind switching manually and it gives me the opportunity to turn off everything for long-term storage.

[dogbert]

I checked the connections, it looks like the ACC switch is grounded to everything else on the dash...that must be your issue. I had a buzzing sound I was able to neutralize with a noise filter, but the voltage isolator must be creating the feedback you're hearing.

I'd separate the power and ground for the stuff attached to the ACC switch to the same circuit as your amps and that should take care of your problem.

[dogbert]

Let me know if you get this figured out.

[NICKYPOO]

Geez Dad, I'm gettin' to it.