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old skool malibu

How does Malibu Wire their stereo with a Perko Switch

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old skool malibu

Just wondering how Malibu sets up there stock stereos with a two battery Perko switch set up. Do they run negatives from the amps to both batteries and the positives to just one of the batteries? And how does this wiring tie into the proper use of the Perko. On my boat with an aftermarket stereo the local shop split the negatives between the two batteries and the positives from the amps go to just to one battery. I am trying to understand how this will work with the Perko switch? Does this wiring allow me to select which battery the stereo is actually sucking power from? Thanks

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Bawshogg

Sounds like the amps are not on the switch then. They are " live " all the time. The way you describe it , you can only combine the two batteries and not switch between the two.

Typically the positives are split to the switch accordingly . Battery one, on terminal one, battery two on terminal two. You have a common pole for output from the switch and your charging lead input. I usually keep all the ground terminals for the amps on one battery negative terminal.

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Soon2BV

Mine is dealer installed, the amp is wired to the deep cycle battery directly, but is triggered on with the power switch from the black box. if the box is off, the amp is off.

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Bawshogg

Of course. That's a given. There is nothing wrong with that setup, just stating the fact that when the amps main power lead is hooked directly to ONE battery, your stereo will always draw from that battery unless you choose the combine setting on the switch, then the switch now supplies voltage from both batteries. You can't toggle between the two for stereo usage.

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old skool malibu

Ok had a look and it looks like the negatives go to battery 2 from the amps and the positives to battery 1. So I would assume I am always pulling power for my stereo from battery 1 then? Is there any issue with the way this is wired? I guess when I am sitting I should make sure I am on battery 1 with the switch for the other accessories pull from the same battery 1 leaving battery 2 clear for starting? If I were on battery 2 with the switch I would always pull from battery 1 for the amps and anything else would come from battery 2 then?

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Soon2BV

Of course. That's a given. There is nothing wrong with that setup, just stating the fact that when the amps main power lead is hooked directly to ONE battery, your stereo will always draw from that battery

Which is what i want. when i am sitting in the cove, i switch to battery 2 for the music. if i run that one dead, then i know i still have a fully charged battery 1 to start the boat.

Love music - Hate rowing

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MLA

Which is what i want. when i am sitting in the cove, i switch to battery 2 for the music. if i run that one dead, then i know i still have a fully charged battery 1 to start the boat.

Love music - Hate rowing

If the stereo is wired direct, then what are you switching from, "BOTH"? The down side is, that you can only draw from one battery or both, not one or the other. There is also the potential for the amp and head-unit to draw from different batteries, this inviting noise.

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Soon2BV

If the stereo is wired direct, then what are you switching from, "BOTH"? The down side is, that you can only draw from one battery or both, not one or the other. There is also the potential for the amp and head-unit to draw from different batteries, this inviting noise.

The "stereo" is not wired direct, it is wired through the boat circuits and on the ignition switch. I have to have the key to on or acc for it to work. When it is on and powered (by battery 1 or 2 or both), it will turn on the amp, which is hard wired to battery 2. If i switch the Perko to 2, i am only pulling power from 2.

if this isn't correct, then i have totally missed the point of wiring the system like it is.

Edited by Soon2BV

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MLA

Soon2BV,

Having the key to OK or ACC is only for the head-units red turn-on circuit. That does not necessarily indicate where the head-units yellow B+ is drawing from. As noted, there is a potential for the head-unit and amps to be drawing from different batteries. Stereo as in the system as a whole, including amps, head-unit, EQ, BT Ipod dock, ect, what ever is there. Having the entire system wired directly to only one battery in a boat with 2 banks and a dual-battery switch is not incorrect, just different. But, having the amps and head-unit drawing from different batteries is not ideal.

Your configuration could also allow you to draw down both batteries, rendering the 2 banks and switch ineffective. Not saying this is the case exactly, because i do not know how your system is wired as a whole, just noting the potential which this configuration as it relates to the OP's question.

If the amp is wired directly to battery-2, you are pulling from it, regardless of the switch, would you agree? The amp is bypassing the switch.

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David

old skool,

Since the thread is about a conventional dual battery Perko switch, I'll offer suggestions on this scheme only, which will not apply to other schemes such as those using ACRs.

Positive:

Nothing positive should go battery direct except a float switch/bilge pump on those very few boats that are stored in a slip and in the water, which is extremely rare for a towboat to not have a lift. Short term memory may be optional.

Every positive should go to the output common (not neg.) terminal of the dual battery switch. This includes ALL audio equipment with no exceptions, the helm buss, and the starter/alternator feed.

If one piece of audio equipment has a positive that goes to a destination or battery then ALL positives of ALL the audio equipment should go to that IDENTICAL destination or battery. The correct application of a dual battery switch ensures this.

It's not a matter of preference. It's a matter of what is happening or can happen within the circuit if done incorrectly.

In this scenario you only have to be concerned with the switch position matching your intended purpose. That means you will have to fully understand the various situational switch functions. In any scheme you are still going to have to pay attention to the switch position. So this is not an extra burden.

Here's the advantage. Regardless of the switch position, it will be impossible for any two audio components to source power from a different battery. That is particularly important so that you are not inviting noise. Here is the other reason. If the two batteries are different voltages, which is often the case, then the correct scheme will not allow the voltage differential to seek a level via the audio components signal path, regardless of the switch position. Thus no conflict is possible.

Keep in mind that if two audio components are allowed under any circumstance to source power from different batteries of different voltages then the voltage difference will travel down the only path that circumvents the isolation which is the RCA ground shield. DC voltage was never intended to take this path. While this ground is normally 'above ground' with a high impedance at the amplifier end, the path is normally common grounded at the source unit end. And with this damage potential exists.

When done correctly, if you have source electronics that are powered via the helm buss and key function, regardless of the switch position, the source electronics and amplifiers will always get power from the same battery or batteries.

Now if there is a considerable difference in resistance between the positive helm buss and amplifiers positive distribution block, then this could cause a small voltage differential and contribute to noise. That is easiest enough to correct by relocating the source electronics supply directly to the amplifiers positive distribution block or a nearby junction block.

Negative:

You will most likely designate one battery as your stereo battery. Ideally, all audio grounds would go to this battery negative post.

I prefer to see the engine block ground go to the starting battery negative post.

You will have a heavy gauge jumper connecting the negative posts of the two batteries.

I like to see a fairly even distribution of connections on the battery posts. This avoids an inordinate number of lugs stacked on one post.

I don't like to see heavy gauge wires and thick lugs on a post shared with small gauge wires and thin lugs.

The same rule applies equally to supply and ground loops. If the helm ground buss represents a resistive path versus the amplifiers ground point, then a voltage difference will occur and noise is a possibility. In that case, you move the source electronics ground to the amplifiers distribution or a nearby junction block.

The most important common ground reference may not necessarily be to the battery or engine block. The most important reference and first priority is the relationship between the audio components.

From here, the switch has four positions. Get to know when each position best applies.

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Soon2BV

So my take-away from this is that i need to move my AMP power connection from the battery to the common power output connection on the Perko switch.

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Bawshogg

Inquiring minds agree that it's the correct use of the switch if you have it, might as well use it correctly.

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MLA

Ideally, thats the best configuration for 2 battery banks and a traditional 1/2/BOTH/OFF switch

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Soon2BV

Ideally, thats the best configuration for 2 battery banks and a traditional 1/2/BOTH/OFF switch

just wondering why the dealer installed it like they did.

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G-Mack

I have 2 batteries and a perko switch from the factory... the stereo and a couple of other parasitic draws are aligned to battery 2.... i haven't spend much time chasing them as it has never been an issue. I need to keep a charger on Batt 2 while in the garage. I haven't invested in a big bank charger just use a C-tek. Not sure if it is memory draws for the black box, amps, medallion etc.

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Bawshogg

just wondering why the dealer installed it like they did.

Probably because they don't frequent TMC?

I mean, it works the way it is. Is there an ideal way to do it, yes. There is always more than one way to skin a cat. It was probably easier for the amp install because the wire runs are a bit shorter that way.

Edited by Bobby Bright

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old skool malibu

Ok thanks all for the info. As my boat only came with the sound pack 1 and no stereo how can I tell where the head unit (black box) was wired to? Right now all positives are on battery 1 and negatives for the amps on battery 2. I do notice a little noise when the boat is running. This wiring my explain why I have some noise. It the fix as simple as moving the positives direct the the common power output on the perko? Or is more work required to see where the black box is going to as well don't need to be concerned which battery the negatives go to?

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Bawshogg

No, you don't want to put all the positives on the common(switched pole) on the perko . This will combine all your batteries and render the switch useless.

I believe on most boats from the factory, the BB is powered from the common B+ bar that runs ton the helm for keep alive power and from the medallion box for switched power.

You want battery 1 +on terminal 1 of the perko. You want battery 2 +on terminal 2 of the perko.

You want the common buss bar wiring( what's in the boat, alt charge back, ect) all on the common terminal of the perko.

You want your amp power leads tied to the common post on the perko, or a lead to to amp distribution block from the common post.

You want all your stereo grounds to the same point/ battery even though they are all connected to the engine block ground that will tie them together.

Hope that gets ya where you wanna go.

Edited by Bobby Bright

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old skool malibu

One other question - pulled the perko off and I have one post labelled output and one labeled input 2. From input 2 it goes over to a main 80amp fuse. There is a post here. Is this where I should run my amp power to? So what is my common post? Also looking further it appears there are 4 factory power wires . One zero gauge heading out of the perko heading somewhere, another zero gauge heading to battery 1 (I think) and a smaller factory power wire heading to battery 2 and a second smaller factory wire heading somewhere. The stereo amp wires appear to be on battery 1 with the large zero gauge factory wire. What I am trying to determine is where my factory black box is wired to and it is my guess that my amp wires should be moved to the common or battery 2. What are these other wires and how do I read the perko as it just shows imput 2 and one says output. The third post is not labelled.

Edited by old skool malibu

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old skool malibu

Bobby to clarify I was only talking the positives of the amps in the prior post.

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Bawshogg

Ok, so the post labeled output is the common post. This is the post that "outputs" voltage. The one labelled 2 is for battery 2. You should have at least three posts if its a 4 position switch. On1, On2, On1+2 , OFF. The other is most likely the 1 terminal. Do you know how to use a volt meter? You can confirm what I am telling you with a simple continuity test.

The other wires you are seeing are the starter lead to the engine, and the buss bar wire that travels under the floor to the bilge and to the helm B+ buss bar. This is usually the wire you see with the resetable circuit breaker attached to it. You may have a charge back lead to the alternator also , but sometimes this is junctioned at the starter and not run back to the batteries as the starter wire can achieve the same results.

If your amplifiers have a distribution block, the main wire from the block should go to the "output"or common terminal on the switch. Along with the wire with the circuit breaker. This is your buss to the helm. No battery leads should be hooked here. And your starter lead should go here too.

Batteries will then go to 1 and 2 respectively. now you effectively have all your audio components powered from the same location on the switch. You can select either battery or both to power everything.

Edited by Bobby Bright

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old skool malibu

Ok thanks Bobby, think I got it finally. I am running 3 monster Exile amps so I have actually 2 zero gauge power wires. Likely they will not fit on this common post but at least I know where it is! Guess the next challenge is figuring how to get these two monsters onto this common post!

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Bawshogg

You may have to run down to the supply house, but you can pick up another small buss bar and make your connections there. As long as your wires are very short from the switch , you will be fine.

http://www.bluesea.com/products/2019/PowerBar_Dual_BusBar_-_Two_3_8in-16_Stud_and_Insulators

http://www.bluesea.com/products/2303/Common_150A_BusBar_-_Four_1_4in-20_Studs

Edited by Bobby Bright

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David

Old Skool,

You should have a master fuse(s) or breaker(s) for all your amplifiers very close (whether a foot or inches away) to the battery switch. Either the output post of a single fuse/breaker or a jumper across the inputs of multiple fuses/breakers should act as a junction.

This way you'll only have one audio cable connected to the switch output post along with the helm buss and starter/alternator feed. That post can handle those three.

If you do need to add another junction point, make certain that all posts are 5/16" minimum.

However, a smaller buss bar is perfect for a reduction to smaller gauge wires and connections feeding the source electronics and other small components, relays, etc. If you step down to a smaller buss bar it should be independently fused between the buss and the power source or use a buss with fusing built in.

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