Help Please!!!

[Plastic_Magic]

Hi all, I have a small problem regarding the wiring of my boat. I have just finished wiring up my boat but all i can see is fine. The small problem i had occuring tonight was that i had the accesories switch on and when i plugged my spotlight into my cigerete lighter it blew the fuse. Now i bypasses the fuse thinking maybe it was drawing to much current? But when bypassed the fuse and and apllied power the the cigarete lighting with no spotlight in it melted the wire on the leg of my outboard motor :o witch i dont have much idea what its purpose is???

Can some won please help.

I have a sneaky suspision that i have a dead short across my cigarete lighter??

But not sure.

Thanks PM

[Angla]

Is the boat a tinny? Are you using the boat as an earth just like a car chassis?
Hope you get to this problem quickly!

Cheers
Chris

[Plastic_Magic]

No the boat aint a tinny, Its a polycraft. I have an idea of wat COULD be happnin just not sure. The main part i have been stuck on is the wire on the motor leg wat does it do? does it just earth the leg or something?

[Aunty Jack]

what wire were on the leg were the prop is?

[Aunty Jack]

does the spotty work on you car

[Plastic_Magic]

Yeah the spotty works fine in car

[Plastic_Magic]

the wire is located on the back of the leg and is joining the bottom and the hydraulic part as well. See pic

[FNQCairns]

Those wires are there to equalise electrical potential, they do not carry any current simply link different parts of the motor together to stop stray electrics from dissolving the aluminium like an aspro.

cheers fnq

[oldboot]

I'd say you have some sort of problem in the negative line of the installation....possibly the main negative common or where the negative bonds to the motor......HMMM... a bit weird.

cheers

[Angla]

It sounds like the ciggy lighter socket has a short. I would investigate further here before reconnecting with that fuse in the line.

Cheers
Chris

[Plastic_Magic]

what i dont understnad is why would it travel and burn that wire out on the motor? mmm ill ask some questions today at work.

Cheers

[yellowbeard]

Thought a sparky would've been in here by now -- but would you accept a mug's opinion? Enter Yellowbeard: One would think that if you had a dead short across your ciragette lighter that it would have blown the fuse long before you plugged in your spotlight. Now in the dumb questions department: Is it conventional to run a spotlight off a cigarette lighter connection (I don't know)? All I can say is that if you try to draw say a 150 watt spotlight from a 12V battery, you will pull 12.5 amps, and that could indeed melt thin wiring and blow a low amp fuse.

[PADDLES]

that's a wierd one plastic. did you actually feel that bond wire? was it hot, did you see it go up? there's no reason for current to flow in that wire if it's a wire bonding the leg components. if it's a wire between something attached to the hull (ie. the outboard bracket) and the case of the motor itself then i'd be thinking like oldboot and there's a problem with your 0v return and it's going back to the battery terminals via the equipotential bonds on the motor.

aaaaaaaaarrrrrrrrrrrghhhhhhh yellowbeard, them there standard ciggy lighters be 10amp usually, and spot on a short in the socket should have fried the fuse well before a spotty was plugged in

[Plastic_Magic]

the funny thing is that i am a apprentice sparky and haveing troubles. lol will work it out though haha. Ill just make the cigarete lighter redundant and see wat happens. Cheers

[PADDLES]

mate, i'd be looking for breaks in your 0v return and maybe a wire rubbed through to your hull as well as a short, the bottom line is that the 12 or so amps that your spotty will be drawing is not enough to melt a bonding wire that quickly. how many sq.mm do ya reckon your equipotential bond is? you should know what currents the different conductor sizes can handle.

[TheRealAndy]

I would offer to take a look for you, but where the hell is Benaraby??

First, if a fuse blows instantly you dont remove it from the equation. You probably want a 15 amp fuse in the ciggie lighter socket.

Without knowing how the boat is wired, its hard to guess as to what may have cause the earth strap on your outboard to fail. Somewhere along the line, the current has flowed from the positive terminal on your battery, through the bonding wire on your outboard back to the battery. How is the negative wire on your ciggie socket hooked up?

Sounds to me like there is a possible fault with the ciggie socket...

[INDULGENCE]

Hey Plastic
Firstly look at the insulation around the cigarette lighter base,I think you will find it touching something it shouldnt.
The wire that burnt is as stated above there to prevent funny power only,however if the polarity of your spotlight is not the same as your lighter connection you may be causing the whole thing to short out and that little wire is doing its job.
wally

[finga]

A full schematic of what you have done would be nice to look at :)
Did you run the negative from a battery or from the motor??
What motor have you got??

Recheck all your connections and the chances are you will find a short.
Also check your polarities ie negative at the ciggy socket is the same potential as your engine block.

That melted wire on the motor should be replaced asap. It's pretty important to stop corrosion on your leg.

[Plastic_Magic]

Thanx guys for the help. Much appreciated. I have come to the conclusion that the cigarete lighter has shorted out. I have made a new wire up and will put on this arvo. Ill rip the cigarete lighter out as i cut the plug of my spotlight last night just so i could use it may aswell get come clips instead. My wiring is all gud as i draw up a diagram and showed my tradesman and its all gud. Must just be that stupid cigarete lighter. The connections on the back are bare so might alson pay to just solder the wires on.

Cheers

[oldboot]

I would offer to take a look for you, but where the hell is Benaraby??

...

head north up past Gingin..... thru Bororon.... keep your eyes out for a speed camera.......then you'll be pretty close to Benaraby........after the turn off to Turkey Beach just before the turn off to Awonga.......plastic you lucky B@####D.....people drive for days to fish your back yard.


plastic mate make no assumptions........ borrow the megger and use the low ohms function to sus out your earthing arrangements.

quite often it takes another fault to darw attention to something else that isn't right.

here is a possible senario.

there is a negative common bolt on the motor.....with a stack of lugs on it....or there are two suposed negative common points on the motor..... but one isn't.

somewhere in that stack there is a bad connection.....either side the connections are fine ( ish).

the power supply negative is on the top with the bonding strap next.......connections good......somewhere in here ther is a high resistance ....then there battery negative bonded to the block and leg via heavy structure.

return current flows into the supply return from the switchboard down the supply negative.....being unabe to flow to the battery directly it flows thru the bonding strap to the leg.....thru the leg and the block back to the battery.
bonding strap not intende to carry heavy current.....an so forth.

purely hupothetical.... but probaly something like that.

cheers

[Plastic_Magic]

Thanx Guys for all your help.

I have fixed the problem with lil work happen to be done. The cigarette lighter was wired with the wrong polarity (STUPI ME) and at the sam time shorting out. Than i open the trim and tilt button in my control box and as in the future my switch is sticky and to stop my motor trimming down i havta press the up button and by pressing the up button it creates a dead short by closing both switches at the same time to operate the trim and tilt. All gud now thanx for all your help

An yes i am a lucky bugger haha (just hope mum and dad dont move :|)

[yellowbeard]

I didn't think that lights had polarity.

[Spaniard_King]

Guys,

I have had this bonding wire burn out on a few newish outboards of late. seems to be something to do with the trim and tilt motor using the bonding wire as an earth return. Unbeleivably once the wire has been replaced it does not do it again

[Noelm]

Yellowbeard is 100% correct.

[Plastic_Magic]

The light doesnt have a polarity but the cigarete lighter was wired up with the outer as active not the end pin. Cause a short to occur.

[INDULGENCE]

Ah yes Yellowbeard may be correct, on a simple light bulb it may not matter. Of course the centre terminal is always recommended as positive and the casing thereby the earth.
The spotlight Ill bet that Plastic was using also has an inbuild charging card and then the polarity becomes crucial.
The plain old cigarette socket also uses the outer case as negative and is the cause of alot of problems particularly in tin boats.
In any boat always use a two wire system/ double insulated and solder all joints no matter how small.
wally

[oldboot]

Ahhh As i suspected..........two faults are usulay required to get a weird one.

It hadn't occured to me that someone would use a metal case cigerette lighter socket in a boat........it will almost certinaly be lightly plated steel and will corrode pretty promptly.

go get a plastic cased marine unit.......they should be back in stock in the shops now (there has been a wide spread shortage of the most common item....altronics, jaycar, bias,whitworths and others source the same item)

as for the soldering thing......there will be ongoing discussuion about that one.....there was a very spirited thread on the subject some time ago......

Oh and make sure any small electrocal items ( like spot lights) that have a metal case have it isolated and not connected to any of the conductors

And as any decent electrician will tell you.......test your wiring before connecting it......we all make mistakes........best to find your own mistakes before they cause a problem.....or someone else finds out;)

cheers