Dumb questions about electrics

[Trevethan]

Currently the electrical system (other than ignition and VHF) on Gayle Louise is dead.

There is a swith panel installed with 8 switched and circuit breakers. Two of the switches are wired up, One goes tot eh Nav lights the other goes to the interior lighting. Neither of which are working at the moment.

The VHF seems to bypass the panel.

I am trying to install a GPS and get the rest of the electrical system working.

When I looked behind the panel, I can see the live coming in. However there is no return to the battery.

There is a cable "floating" around behind the panel (its blue or black can't recall)and wen I make a circuit between this and the live with my multimeter it reads 12.6v.

I guess this needs to be somehow connected to the panel in order to complete the circuit. The question is where as there is no obvious connection point?

Also should I wire up the VHF to the panel or let it continue as is?

Any help or suggestions are welcome. And I suspect I will have more dumb questions later.

Thanks in advance,

Nick


PS Ccscott, it was the starter motor as you suspected! Lucas did a poor job of the refurb the first time round!

 

[ccscott49]

Thanks for that! The blue/black wire is obviously your return negative, to confirm this, find the other end, it should be down at your battery connections, find it and confirm with a multi meter that it is, with the continuity tester. Then, behind the panel, should be a negative busbar, where the wire fits and any other wires from the returns from lilghts etc, should go to. This then completes your circuit when switched on. Have a look anyway. It's impossible for me to know whats going on without looking at it, it's one thing fault finding, but quite another when you actually need to put your hands and eyes on something. If there is no negative busbar, you need to fit one, although I cant believe theres none there, even a negative stud somewhere. By the way, insulate that wire for now!

 

[gtmoore]

Interesting you should say that the VHF is not wired through the switch panel as mine is the same and wondered why. It has a completely separate fuse and switch for some reason.

 

[Trevethan]

I was expecting to find a bubar (its usually a length of aluminium alloy isn't it?) and as far as I can see, there isn't one/

The panel made up int he following way. A live wire leads to a terminal on the circuit breaker. Each live c-b terminal is wired to the next. From two of the c-b's a wire leads from the other terminal to a terminal on the switch. A push on connector links this to the lights etc. The other connector also runs to the lighting circuit, (presumeable the -ve part of the circuit)

Should I acquire a bus bar and solder a wire from each -ve terminal on the switch panel to it?

Or maube I should just replace the panel? The panel is an all in one with battery monitor, oil, temp, rev counter (these don't work), engine timer (works!) and ignition set it.

Regards,

Nick

 

[kingfisher]

VHF always directly wired to battery

For safety reasons: the VHF should always be wired directly to the battery, bypassing all switches. It has to be properly fused, of course.

In case of emergency, you migt not have the clarity of mind to first switch on the battery switch, and then switch on the VHF power at the panel, and then switch on the VHF.

The VHF should always be powered.

Obi-Wan
http://sirocco31.tripod.com

 

[ccscott49]

Re: VHF always directly wired to battery

Quite correct! It's a pity you see so many wired through the switch panel!

 

[halcyon]

Very rare to find a neg busbar on a switch panel, if there are lights by the switches, or illuminated switches, you will find a neg for the.
To make a simple bus bar, take a choc block connecr=tor, loop a bare single core down one side, bring in neg from battery to one end, terminate boat negs to remaining. Sean lots that have been at sea for 15 years without any corrosion. Alt arrange a bolt, through a bulkhead if around, fit eyelet terminals, fit to bolt.

Seperate vhf supply were normally after market fits, or bad installation, that caused interference..

Brian

 

[Trevethan]

Re: VHF always directly wired to battery

Ah well, at least one thing one thing on this boat has been connected up properly!

Regards,

Nick

 

[Robin2]

There is no reason for the negative wire to be connected to the switch panel unless there are lights on the switch panel.

Remember the negative wire is unlikely to have a fuse or circuit breaker so be very careful it doesn't contact the incoming positive wire to the switch panel.

 

[chippie]

Surely a negative wire is needed to cmplete the circuit.

 

[Trevethan]

So the circuit should look like this.. Hope it displays correctly




From Battery switch ve.....Circuit breaker......switch.........Lights........
00000000000000000000000000000000000000000000000000000000000:
00000000000000000000000000000000000000000000000000000000000:
To battery -ve.................................................negative busbar.....

<P ID="edit"><FONT SIZE=-1>Edited by Trevethan on Fri May 31 10:40:13 2002 (server time).</FONT></P>

 

[gtmoore]

I think the negatives all come together at a common point and this may not be at the switch panel - mine are all under the chart table for some reason!

 

[gtmoore]

Re: VHF always directly wired to battery

I see - well that makes sense. Unfortunately my setup is only half way right as it still takes the feed to the seperate fuse from the battery switch. I didn't rig it up myself but maybe this could be to allow the VHF to run from either or both batteries perhaps?

 

[Trevethan]

Re: VHF always directly wired to battery

Mine too runs via the battery switch. I can't see this being a huge problem. The switch is reliable. easily accessable and the first thing turned on when entering the boat and the last thing turned off when leaving.

Its also close to the radio itself so the time taken to switch on if it ever were off and an emergency arose is about 6 seconds.

In addition, a quick turn of the radio's on off dial and a spin of the squelch control acts as a final audible and visual reassurance that this time I did remember to turn the battery switch to off!

 

[Shanty]

First - before poking around amongst the wiring, it would be prudent to disconnect the battery - one wire has broken loose already & there may be others about to do so. A short across a battery can do a surprising amount of damage.

Second - if you intend using the existing wiring, rather than ripping it all out & starting again, I would suggest you draw a circuit diagram of the existing installation. Label each of the wires at both ends as you identify it - a tag of masking tape will do, with a name or number on it. Record the names / numbers on your circuit diagram.

Once you have completed the diagram, check that each light / piece of equipment has a complete circuit from the battery, via switches, circuit breakers, connectors etc to the light / equipment & back to the battery. If you can't complete the circuit, either you missed a wire, or a wire is missing.

All of this will take time, but at the end of it you should have a working system, and a good record of how it works - for future reference.

Get the existing setup working as you want it, and then think about additions - one problem at a tme.