serious electrical issue

Discussion in 'OnBoard Electronics & Controls' started by ho0osierdaddy, Apr 6, 2009.

  1. ho0osierdaddy
    Joined: Apr 2009
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: ohio

    ho0osierdaddy New Member

    Here is the situation, please bear with me as i describe this. I have a 1984 wellcraft sportsman that is giving me fits. I have an issue where my needles on my gauges all move when i try to turn on any switch on a panel. the light in the cabin comes on when i turn on my batteries although very dim. i removed the fuse and it still comes on. like it is feeding through the negative. my main panel under the dash is only showing 4.5 volts. my ground to the engine looks good. and i can't find any positive and negative wires touching anywhere. if i flip on my switch for my running lights the lights come on although dim yet when i have them switched off the light stays on though really dim. i have removed all negative wires from my batteries and it still stays on as does the cabin light although again they are dim (4.5 volts?) nothing works that is on my main panels under the dash. if i unhook the cabin light from the terminals under the dash the running lights go out as does the cabin light at the same time and some of the switches on the panel work although they are dim (lights for compass, panel lights, horn barely makes a noise. then when i hook my cabin light terminal back up i hear the fuel gauge making a noise (i think from the needle on the gauge .
    all of the the big things work fine , motor cranks, (I/O) trim tabs and the tilt and trim i am guessing these are all direct wired but istill need to check for sure. my radio doesnt work (am/fm) and the last time i used me ship to shore last fall when i keyed my mike it pegged my gauges. i have a new ship to shore radio to install and have removed the old one by un plugging it. the wires still have the old connectors on them, so i am sure that isn't an issue? i am pulling out my hair and can't figure this out. any thoughts?

    i know to check all connections and i have. the main thing i need to know is does this sound like i have a negative wire touching a positive some how? maybe a screw penetrating a wire? and if so how come i dont have any melted wires? and why do i only have 4.5 volts on my main panel under the dash? is this a ground issue or what? thanks for reading and any advice you can give.
     
  2. TedZ
    Joined: Jan 2009
    Posts: 23
    Likes: 1, Points: 0, Legacy Rep: 11
    Location: Glens Falls, New York

    TedZ Junior Member

    When you remove the negatives from the battery the lights still stay on?? Don't let anyone know! :--)

    OK. With the engines off and all of the wires removed from the negatives from all of the batteries AND the boat unplugged, the lights had better be off. If they are not, you have a battery you haven't found.

    Assuming no mystery battery, plug the boat in. If the lights are now dim is there a 12 VDC compact fluorescent or 12 VDC fluorescent light somewhere fed by 110 VAC. If there is, it has died and when they go bad the ballasts will cross feed to neutral. I honestly don't think that is the problem but with the lights dim and all negatives disconnected...

    The next item is similar. Anything that has a 110 VAC power supply but is operated on 12 VDC or close needs to be checked. Wall wart power supplies, radios, computers and even some appliances run on DC but are plugged in to 110 AC. Disconnect and/or unplug all of those until the lights go out. You must find that and throw it out or replace the power supply.

    Now it is simple. You lost a neutral to the panel and an opportunistic connection was made to neutral as described above. If the appliance was made in China, focus on that on by the way. All of the rest of the symptoms you describe are the neutral lost problem. Make a jumper from 12 or 14 ga. wire long enough to go from the battery negative to the panel. Put appropriate sized alligator clip on both ends. Feed the 12 VDC negative to a gauge, a neutral bar or anything you like to insure a good neutral to the panel. Stuff should work. Keep making connections closer to the battery and you can isolate the bad connection.

    Hope this helps,

    Ted
     
  3. rasorinc
    Joined: Nov 2007
    Posts: 1,854
    Likes: 70, Points: 48, Legacy Rep: 896
    Location: OREGON

    rasorinc Senior Member

    Are you sure you have marine wire throughout the system? This is a 25 year old system and you may have general wire failure. Just a thought.
     
  4. Landlubber
    Joined: Jun 2007
    Posts: 2,640
    Likes: 124, Points: 0, Legacy Rep: 1802
    Location: Brisbane

    Landlubber Senior Member

    "i have removed all negative wires from my batteries and it still stays on as does the cabin light"

    OK, do this again, and physically remove the shore power cable.

    Lights out, then plug in the shore power again....lights on....you have a leak from that source.....there is , unfortunately, no way you are going to have lights on if the neg terminals are all removed unless there is a AC leakage through somewhere.

    Also check components for back up power sources, such as NiCad batteries, you obviously have a bad circuit somewhere, it is just a case of trial and error...you will get there mate.
     
  5. peter radclyffe
    Joined: Mar 2009
    Posts: 1,405
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    Location: europe

    peter radclyffe Senior Member

    In the early 80's Evode & Wellcraft got together & attempted to produce a batteryless boat, (what else is a boat but a floating battery ), on the stbd number 3 frame they placed the positive terminal, & on the number 11 frame port side the negative terminal, it appears you have the prototype for a series that they decided not to produce
     
    1 person likes this.
  6. Landlubber
    Joined: Jun 2007
    Posts: 2,640
    Likes: 124, Points: 0, Legacy Rep: 1802
    Location: Brisbane

    Landlubber Senior Member

    Peter,

    Just as well eh.
     
  7. Frosty

    Frosty Previous Member

    You have a winch battery?
     
  8. CDK
    Joined: Aug 2007
    Posts: 3,324
    Likes: 145, Points: 63, Legacy Rep: 1819
    Location: Adriatic sea

    CDK retired engineer

    Long distance diagnosis:
    Corrosion of the ground terminal behind the console, in the plug that connects the main cable to the engine or - even nastier - the extension plug .
    Engine manufacturers like Mercruiser and OMC supply a standard cable that is barely long enough for a 15 ft. sports boat. For anything longer, they sell an extension cable. The plugs are the same rubber things like near the engine, but they lie in the bottom somewhere behind a panel or behind the gas tank.

    I also have seen devastating damage caused by earth wasps. They build nests from a clay-like substance and prefer quiet locations with lots of electrical wiring.

    Engine bay components are not affected because they are directly connected.
     
  9. Landlubber
    Joined: Jun 2007
    Posts: 2,640
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    Location: Brisbane

    Landlubber Senior Member

    CDK...bloody mud wasps.....reminds me of a time I simply could not get a motor to run right, seemed to be starving all the time....took two days work to find MUD WASPS had blocked the tank vent, made it run for a while then slowly shut down the show....nature getting back at me for being nasty somewhere eh.
     
    1 person likes this.
  10. CDK
    Joined: Aug 2007
    Posts: 3,324
    Likes: 145, Points: 63, Legacy Rep: 1819
    Location: Adriatic sea

    CDK retired engineer

    And they love boats!
    Some of the nests I find when the winter is over and the tarpaulin removed are well over one kilogram and contain 100's of larvae plus many embedded small spiders as their prime food source.
    They are a nuisance anywhere, but along the coast the substance contains salt. When nests are built at the back of instruments electrolysis dissolves the copper from wires until there is really nothing left but empty PVC tubes and green clay.
     
  11. pistnbroke
    Joined: Jan 2009
    Posts: 1,405
    Likes: 33, Points: 48, Legacy Rep: 404
    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    First rule of boat wiring

    If operating one system causes another to go on or off its a fault in the negative (earth ) loop which feeds multiple items
     
  12. Frosty

    Frosty Previous Member

    Hes right,--press the foot brake on a car and the tail lights go out its always the earth to the frame.

    Quite simple really because if the earth is not secure or partly the supply from one system can not reach neg so goes back into the system through the other and ballances out the volatage,--so no flow.
     
  13. pistnbroke
    Joined: Jan 2009
    Posts: 1,405
    Likes: 33, Points: 48, Legacy Rep: 404
    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    thats some rep points then ??? What I advise the original poster to do is to take a length of cable and start at the battery neg and go around the boat attaching the earths for the different fittings as you go and then back to the battery negative .remove any crap wiring as you go ..that will sort it.

    Frosty your observation on rear lights is spot on but your explanation deserves 0/10 if I was marking your exam paper.
    In the case of the stop tail lamp set up if one earth is removed the tail lamp gets its earth through the two stop lamps and appears to work normally. As the stop lamps are 21w and the tail lamp 5w the current through the tail lamp is insuffifecient to light the stop lamp. When the foot brake is operated you have +12v to both filaments and no earth so nothing lights .
     
  14. Frosty

    Frosty Previous Member

    CRIPES WHAT DID I SAY?

    Isnt that what I said. Is it you that deducted me points for that? Who do you think you are you an examiner?
     

  15. Frosty

    Frosty Previous Member

    What are you talking about? you cant put me up one point which you have.nt.

    The point system is for rude behaviour. When you have been here as long as me you will get the power to whack 25 points which is why I dont use it.

    No one put you here as an examiner and my "technocrap" was the same as what you said.
     
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