Ground loops and proper wiring? Home Run? HUM, Hiss, POP

[Earmark Marine]

This is my best guess.

It's not normal so it can be fixed.

You have dealt with the stereo side but perhaps you should look closer into the supply and ground on the sonar side and the condition of the connecting cables. All power to the transducer would extend from the gauge/module end, correct?

If the sonar system is back feeding noise into the DC boat supply you can remedy this with isolation or filtering. If the noise is induced through the air the problem is with the sonar wiring/connectors or faulty sonar equipment.

Try opening up the gain on one highpass amplifier and use a cut long RCA cable to sniff around for the source of radiated noise.

Back to the stereo, with any noise diagnosis, you begin with the very last component in the signal path in isolation, and work your way back in reverse one component and connecting cable at a time.

Use a logical isolation strategy to replace all the long hours of trial and error.

David

[WakesetterE]

Ok, when it warms a little I'll go test in the water and see if this is my only remaining noise issue in the boat....I'm afraid to replace the transducer only to find the depth finder unit causing the issue....From the searchs it appears many boats my age have had the depth finders replaced.....the noise is certainly induced thru the air as the stereo equipment is completely separately wired to its own battery at present, with completely separate grounds, etc...

[WakesetterE]

Final update on this post just in case anyone has a similar problem like mine. The noise issue I have been chasing is now gone. The factory depth finder was radiating noise like crazy into the stereo. It was random, sometimes a crackling, sometimes popping, sometimes a pop,pop, pop, pause hiss. The factory depth finder appeared to worked fine. I tried rewiring it, searching for cracks or splits in the transducer cable. Even with the transducer cable disconnected, it radiated noise. Even with the stereo on its own battery completely isolated, it radiated noise into either the HU, rca cables, or wiring. The problem was so weird. I added a preamp and EQ and the noise was very loud. Spend a few hours on the phone with Audio Control. They were baffled. When i removed power from the factory depth finder, the noise is gone. Even better, the Hummingbird 650 is a direct fit replacement, was an easy install, and does not cause noise in the stereo system. Best $100 bucks I've spent in a long time. If you have an older boat with the factory depth finder and you suddenly have noise in your stereo, consider disconnecting the power to the depth finder....it may be the cause. I rarely remove items that appear to work making this an extremely difficult find and fix for me.

[Stevo]

I am having the same popping issue upon ignition (stereo resets) and a constant engine hiss while running, i added a 2nd battery last year and a Perko switch. while out last weekend 1/2 way through the day, i had difficulty turning the engine over because not enough battery juice. (although both batteries were purchased last year, and 2amp trickle charged the day before.) I though there was a problem with the way i had the perko wired because the terminals on the #2 battery were wicked hot... I disconected the 2nd bat and ran just on #1 and it fired like normal.

I pulled the perko today and I had it wired as it shows per the diagram..

Both Batteries are in the forward locker so there is a 12-15ft run of +/- 2g wire from bus / block in engine compartment to the perko.

Negative cable runs from block to negative terminal on Bat-1, then to bat-2,

Negative cable to amps conected to Bat-2

Positive Bat-1 goes to term-1 on perko

Positive Bat-2 goes to term-2 on perko

Positive output from Perko has 2 wires out

1- alternator - 2 gage

2- to in line fuse then to amp-1, and amp-2

Qestions ????

1- what red flags are there so far ??

2- The 2 gage + out from perko runs to rear locker where it splits to the bus for the alternator, and to distribution block at the helm is that correct?

3- WTF??

Here is a quick diagram.

[Bozboat]

Where does your negative wire from the head unit terminate? If its on the bus bar under the dash, move it to the same place the amps ground.

Also, where does the head unit get power?

[Stevo]

Head unit grounds under dash, same with +

Figured running 25 ft of +\- wire all the way around the boat was increasing the opportunity for problems.

[Bozboat]

Head unit grounds under dash, same with +

Figured running 25 ft of +- wire all the way around the boat was increasing the opportunity for problems.

Move/extend the head unit ground to the same battery terminal as the amps.

[MLA]

Your diagram also show you daisy-chaining the B+ for amps-2 off of amp-1. Is this the case?

[Stevo]

Your diagram also show you daisy-chaining the B+ for amps-2 off of amp-1. Is this the case?

No, I have separate fused + connections, sorry my art work was a quick sketch

Move/extend the head unit ground to the same battery terminal as the amps.

ok will do, what size wire should I run??

Edited June 23, 2013 by Stevo

[Bozboat]

18? Something the same size as the head unit wire

[Stevo]

18? Something the same size as the head unit wire

Ok, thought so but because of the long run I wanted to be sure.

[shawndoggy]

in the interest of overkill I would do 12 Awg... in case you may ever want to power some other stereo accessories like an eq or bluetooth dongle or ipod cord or...? then you would never worry whether 18 awg was enough.

[Bozboat]

in the interest of overkill I would do 12 Awg... in case you may ever want to power some other stereo accessories like an eq or bluetooth dongle or ipod cord or...? then you would never worry whether 18 awg was enough.

Overkill es bueno

[Stevo]

ok,

12g it is but i need to hit the hardware store for the run.

here is a pic of everything cleaned up and put back together, (minus the ground for the head)

Blocks look familiar Boz, (thanks again)

I was trying to get this wrapped up early to make a run today, but cool overcast , breezy combined with fair weather friends = try aagin next weekend.

[Stevo]

and yes i will be adding a drainage hose to the cup holder,

I was thinking of tying it in to some sort or receptacle to catch the water instead of draining to the floor, anyone know if someone has rigged this up before?

I don't plan on taking copious amounts of water through my cup holders but... "Overkill es bueno"

[Bawshogg]

Just run the drain hose over to where the blower hose goes onto the bilge. Drain excess water from the cup holder right to the bilge.

[Stevo]

Just run the drain hose over to where the blower hose goes onto the bilge. Drain excess water from the cup holder right to the bilge.

That is a 12-15ft run under the rail back to the engine compartment.

[Bawshogg]

Nope. Those fresh air tubes in the compartment just dump into the bilge. The big black ones that look like dryer tubing. Where they come up from the floor, just run your drain tube into that hole. Usually the wires come outbof it also.

[40oz]

I know this is an older thread, but what if you have two batteries with a selector switch. Where should you place your distribution block? I feel I have the same common ground, common power source hum.

[shawndoggy]

Jimjom if its a perko type 1-2-all-off switch, power (+) distro should come from the perko common post.

[40oz]

Thanks,

What about ground? Battery 1, 2 or have its own distribution block?

[Murphy8166]

All the groung will end up at the negative terminal of the the battery or batteries. So the boat ground and stereo ground can go the same battery....and if you have another battery - you would ground it to the battery with all the other ground.

I have even seen folks split the ground b/t the two batteres. One of battery one and another battery two. In a parallel wired system...this is no issue.

[shawndoggy]

so on the ground side, batteries 1 and 2 are tied together. You can ground to either battery from each amp or you can run a distro block (which itself is going to go to either batt 1 or batt 2). Your call. How many amps?

[40oz]

2 as of now

[shawndoggy]

so with two, whether you do a distro block or just make two runs to the common post is up to you. If you think you might expand, it's nice to have a distro block with some open slots.