EE with Electrical Issues

[daydreamerbob]

Well I do have the degree - but you know - solving math problems is a heck of alot easier than pulling cable

anyway

Put in a Stereo with 2 speakers - works great on the trailer

Go to the gulf of mexico - one speaker doesn't work lots of interference and low volume

in frustration tear it apart and put it back together - speaker works - still no volume

next day on gulf doesn't work

go home on trailer works like brand new

go to lake - low volume, interference and one speaker not working

so - it seems to me i have a ground issue - and would really just like someone to tell me what to do rather than go in to full blown troubleshoot and isolation mode -

Thanks fellas

[MadMacX]

One step at a time:

Does the system ground go directly to the battery?
Are you sure that that you are using both front speaker or both rear speaker wires to connect the speakers?
Are you sure you have the positive speaker output to the positive speaker terminal?
Where and how is the antenna mounted?
Does it make a difference if the engine is running?
Does it make a difference if you are on shore power?
Do the speaker wires pass by anything that generates power?
Where did you mount the head unit?

Good Luck,
Pat

[Kelly Hanson East]

you have a bad connection somewhere...go back and look at your solder joints and or connected. If its a real bad day, you have damaged your speaker wire pulling it through your boat and the damage will be hard to find. Troubleshoot that by running new wire inside the boat to the speakers (without pulling behind liner) and confirming proper operation.

You know the fix for that, unfortunately...

[Hamin' X]

Can't tell you how to fix it. Not enough information and the info that we have is subjective. However, I suggest that you take one of two approaches. Simulate being on the trailer when it does it on the water, or simulate being on the water when it behaves properly on the trailer.

When on the water, start turning of other circuits one at a time. Possibility that a something that you use while sailing, or motoring is causing the interference.

When on the trailer, start powering up things that you use on the water.

Hunt and peck method. ~Rich

[Currie]

Hmmm,

The word "interference" isn't indicative of a loose speaker wire. Unless interference sounds like distortion caused by a crappy connection as Stephan suggests. But if I really heard interference (funky modulated tones and weird stray signals), I'd also suspect a system grounding issue. Only problem is, there really isn't a ground, just a "floating" ground - i.e. the battery's negative terminal. Ground loops could still be an issue, though. I guess I'm kind of suspecting the stereo itself - bad internal solder joint, etc.

My $.02 - Good luck!

~Bob

[Andy26M]

Hmm -

The comments that jump out to me are that it works fine while on the trailer, then doesn't work fine while off the trailer. Says to me that something changes state when the boat is launched which messes up the radio. Then it changes back when the boat is recovered.

So, what do you change when you launch the boat?

- the mast is raised
- the engine is lowered
- maybe the battery switch is turned to "both" instead of "1" or "2" ? or vice-versa
- certain breakers are turned on/off

I'd run through the process of launching the boat, check the radio after each step, and find out exactly at which step of the process the radio stops working properly. That may point out what is causing the ground/interference/etc.

- Andy

[TAW02]

You say radio ap ain't bust'in loose on the water? But on the hard it kicks arse. it'll do that. Yeah. It's a radio (analog) rf is ripping off the antennae side, radio is housed in a farady cage sort of speak. A punched metal housing.

Just make sure the outer housing is grounded. Should have a screw lug on the housing somewhere. Make sure it is terminated.

Good luck Dude

Big T

[daydreamerbob]

some more info

but first thanks for all the good advice!

the "interference" or static referred to is with respect to my ipod - plugged in via aux jack on the face of the unit.

the unit is installed just above the mirror all the way outboard just above the factory light and i cut power in from the lighting circuit.

on land - music from ipod loud - stereo and outstanding

on water - music from ipod mono - (one speaker not responding) - and very limited increases in volume available - with unit and ipod all pegged high.

i am not confident in the connections - as pushing the flotation foam back into the overhead is certainly tugging on wires - but not sure it explains work on land not on water....i was hoping for this to me a common - oh you dumba$$ type problem - but i guess i need to do the steps...

anyone use wirenuts? the inline connectors really stink

[Hamin' X]

anyone use wirenuts? the inline connectors really stink

IMHO, the only connection worth making is a soldered one that is sealed with waterproofing shrink tubing, or liquid electrical tape. All others are subject to corrosion and/or vibration failure.

~Rich

[Don T]

Hello,
We might not want to think about it but the fact is, the shape of the boat changes when on the trailer or in the water. I suspect liner clearances tighten and loosen, wire gains and looses tension. I know with our boat, the head door doesn't fit well on the trailer but works great on the water. Stereos these days are running bridged amplifier outputs to the speakers so neither wire can be grounded.

Food for thought,
Don

[craiglaforce]

My guess would be that you have your ground bonded to a through hull or the motor skeg. This would have no effect on the trailer, but in the water would ground to the water. Now how that would affect one speaker and not the other escapes me. Or maybe you have the boat plugged into a charger in the water at a slip and you are getting some interference? Or maybe the boat next to you has a boat that is bonded to a through hull and an improperly wired shore power supply on a non-isolated charging transformer and is putting some AC ripples into the water that is getting back through your system. Or just electrical interference is hitting your speaker wire from someone's radar or ?. twisted pair? twisting helps cut RF interference. Are you putting the boat in the Bermuda triangle?

[Kelly Hanson East]

Im sticking with bad wiring. Run some test wires to your speakers without running them behind the liner and I bet the problem is solved. The one speaker thing pretty much wipes out the bad ground theory imho.

[MadMacX]

Bob,
I tend to agree with KHE, however, I also don't think that using the light wire as a power source is the right thing to do. You should really run separate power/ground cable. Also, NO wire nuts!!! Hamin' X is spot on with solder and joint protection. You may want to checkout your ipod cable and make sure that, 1) it is a stereo cable and 2) it is fully seated in both jacks. Does the stereo work OK when not plugged into the ipod?

If you are not 100% sure of your wiring.........to paraphrase an old sailing adage "When in doubt, rip it out".

Good Luck,
Pat

[Currie]

DDBob, One more thing - just in case...(Pat made me think of this)....

When you say iPod do mean an actual iPod? Or a cell-phone-type MP3 player? I ask because the connector on many (most?) cell-phone MP3 players is not a stereo plug/jack. It's a stereo + microphone jack, and so it has three hot-wires plus a ground (i.e. three black-rings, not two). If you plug a standard stereo plug into a stereo+mic jack or vice versa, you will indeed only get one channel to play, and possibly a floating hot on the other channel. Sometimes you can actually get it to work by inserting the plug part way. Make sure your jack and plug are apples and apples (two-ring stereo, or three ring stereo + mic).

Just a thought,

~Bob

[tangentair]

I read through this kinda quick - but missed if you said the motor was running during this "interferrence". And I missed the part about the antenna mounting if there is one.
There is not enough for me to say definatively but I would look at the ground to see if you are using the trailer/towing vehicle as part of the "on trailer" circuits. I would look to see if the ground to/from the engine is isolated from the radio's ground and if they are running off the same battery/power source. "On the trailer" is the battery being charged and/or is the main switch in the same position as when underway? The same with the speaker return are you using a ground that is being switched differently when underway?