Where is the ground on a boat?

[WDC]

I was installing a bilge pump and was reading the diagram. I noticed it showed the battery grounded. What should the battery be grounded to? Maybe it is grounded and I am not aware.

1973 Glastron 85 hp johnson

 

[gcheris]

Re: Where is the ground on a boat?

WDC, the battery negative terminal is the ground. It may be connected to a ground block to which you can connect the rest of the negative (ground) leads.

 

[tashasdaddy]

Re: Where is the ground on a boat?

the black wire is the ground wire,

 

[excalibur-oc]

Re: Where is the ground on a boat?

WDC
I think I know what you are refering to.
In a schematic wiring diagram for a TNT solonoid I noticed it showed the battery with a ground wire off the negative terminal going to 3 lines ( universal symbol for ground)
As far as I know fiberglass makes a poor ground.
The negative term. of the battery is ground.
Poor ground causes so many irrating problems with anything electrical so I have wired my boat with a common ground wire right around and used buss bars under the dash in the bow & stern to ensure I have good ground.
Everything is grounded directly into a buss bar.

Unless you are the first owner or you did tour own wiring check to make sure what you think is a ground wire is indeed ground.

 

[Texasmark]

Re: Where is the ground on a boat?

Everything on your boat should be referenced to your engine's running battery - (NEG) terminal unless you have a yacht and have an APU.\

If you have a metal boat, run a dedicated wire from the hull somewhere to the - batt term. This is a "static" ground, not a current carrying ground. Keeps he hull from developing a static charge that could blow out some of your electronics......in a remote situation...seldom happens but could.

If you have a 24V trolling motor system, the - terminal of the 12v battery that serves as the lowest voltage of the two should also connect to the engines running batt, - term to insure that there is no static elect buildup on that system; but it is not absolutely necessary.

Mark

 

[J BLANK]

Re: Where is the ground on a boat?

Since we are talking about ground wires i have a quick question i hope someone can help me with. i just purchased a 2001 Straus with a 115 Evinrude and after i had it a week or so i put it on the trailor for a week and when i took it off the trailor but the cranking battery was dead, i never thought to check it before i put it in the water because it had just been out of the water a week and i had charged the cranking battery fully after i took it out of the water, something must be draining the battery. now to the question, what is the best way to check to find out what is draining the battery i know its good because i put a new one in when i bought it.

j blank

 

[Texasmark]

Re: Where is the ground on a boat?

Is it an external circuit or a bad battery. Repeat the process (were using the boat and when you put it up it discharged the batt) and prior to storage, remove one of the battery terminals. Will answer the question.

If the battery holds with wires disconnected it is leakage in an external ckt. If not get another battery.

Take your VOM (Volt-Ohm-Meter) also known as a multimeter and get on the 10 A scale. Remove the + lead to your battery, with everything off and connect the 10A ammeter between this lead and the battery terminal it was connected to. If you get the polarity backwards, the meter will peg behind zero. If you read any amps, you have an external leak and that is the reason for your discharted batt.

Simple matter of watching the amps and undoing things till the amps drop to zero whereupon you found your culprit......the last thing you disconnected.

Mark

 

[J BLANK]

Re: Where is the ground on a boat?

thanks, texasmark. i will proceed as you have instructed and see what i find out and i do appreciate your help.

j blank

" Thats why they call is fishing and not catching"