short

[capeannfisherman]

Thought I found all the shorts, but I didn't. I still have a short to ground in the main switch panel. Any switch I turn on causes a short between the hull and +12 volt lead. I would think this would blow a fuse, but it has not, so I'm having trouble finding the short. Removing all the fuses removes the short, but if I put back in any fuse the short returns. This indicates the short is not on the load side of the fuse but on the switch wiring itself. I wish I had the scematics of how this boat was wired. Does anyone know if these are double pole single throw fuses? How is the fuel gauge wired? Is it fused too?
Adrian

[welder]

I'm confused, Hull to +12 lead ?

Are you melting wires or draining the batteries over night ?

You will pick up a ground from the motor to the hull so if your on the pos. side of the batt you will make a circut thru the hull.

[capeannfisherman]

That's right. I turn the battery off when not in use to prevent drain down. I've found this happens only when using lights, horn, or wipers. Anything on the switch panel. I've talked to An electrical engineer about this and we have decided it is a poor ground (-) connection somewhere. Now to find it. To find it I will start with a volt meter between the negative terminal of the battery and all grround connections on the switch panel. They sshould read 0 volts.. If I get a volt reading I'm getting close.
Adrian

[Ironwoodtuna]

Adrian, Post some pixs of your fuse panels and battey switch so we can get some ideas what your dealing with. mty

[Daddy'O]

If I’m following you correctly, you’ve got what we call a “resistive” short. In other words you are “leaking” current (very small amounts, possibly in the ua or low ma range) from your battery through some component (load) to ground. Now if I understand correctly, your battery is draining (slowly) if you leave your switch on – correct?

If you had a direct short, your battery would become a welder & you would know exactly where your problem is.

Not knowing how your boat is wired for the lights, horn, or wiper I can only throw out some suggestions. Are your lights switched through relays? I’m sure the horn is. Relays can become leaky. How about that wiper motor? The motor windings can become leaky too.

Do you have access to a clamp on amp meter that can read very low current? If you do, this would be a better tool. I also suspect your voltage reading will be in the mV range when you find your trouble.

Hope this hasn’t confused you. Best of luck!

Wayne

[capeannfisherman]

Camera is on the fritz. Need to shop for a new one. Worked on it today and I think I have it narrowed down to the running lights. They didn't come on when I turned the switch on and then when I walked up front to check them they came on, so I must have a lose connection somewhere. I've been talking to Paul an electrical engineer about the problem and I think we are getting close, but still haven't found it yet.
Adrian

[Ironwoodtuna]

I know you know this, but...I trust that all your negatives are NOT connected to the boat hull, but are direct to the battery ground. mty