Battery Issue?

[KevinP]

I have been fortunate to find answers to my questions with a quick search but I am looking for some help on this one. I was replacing my battery terminals and my wrench touched the compartment door, which is aluminum, and gave a pretty good spark show. Should the hull be grounded or is there a issue with the wiring? The boat is a 2002 Pro V, thanks.

[Hot Runr Guy]

Originally Posted by KevinP

I have been fortunate to find answers to my questions with a quick search but I am looking for some help on this one. I was replacing my battery terminals and my wrench touched the compartment door, which is aluminum, and gave a pretty good spark show. Should the hull be grounded or is there a issue with the wiring? The boat is a 2002 Pro V, thanks.

Almost always, the hull gets grounded thru the outboard mounting bolts, so if the OB positive cable was still attached to your battery, there's your path.

If you have a voltmeter handy (who doesn't?) disconnect the motor positive cable from the battery, and check from the battery positive to the hull again.

HRG

[Hawker]

Originally Posted by KevinP

I have been fortunate to find answers to my questions with a quick search but I am looking for some help on this one. I was replacing my battery terminals and my wrench touched the compartment door, which is aluminum, and gave a pretty good spark show. Should the hull be grounded or is there a issue with the wiring? The boat is a 2002 Pro V, thanks.

To understand correctly, I'm assuming that you were tightening the + (positive) terminal at the time of contact with the compartment door when you got the spark show?? If that is correct, that is a good indication the hull of the boat is already grounded, or bonded to the battery - (negative/minus) terminal, and like HRG said, it's likely because it's grounded via the outboard mounting bolts to the transom! If that's the case, that's why you got the sparks when you made accidental contact with the door with the wrench! Also like HRG said, having a good voltmeter will assist you greatly! Unlike HRG says though, disconnect the - (negative/minus) cable at the battery making sure the lead is isolated from touching "anything"! Now, place the red lead of the voltmeter to the + (positive) terminal and the black lead of the voltmeter to the - (negative/minus) terminal of the battery. Your reading should be "zero" as you have isolated the - (negative/minus) cable and "path" for a complete circuit!

Carefully reconnect the - (negative/minus) cable that you disconnected and isolated and tighten, then carefully disconnect the + (positive) cable and isolate it as you did the negative cable. Now, touch the + (positive) post of the battery with the red lead of the voltmeter and the compartment door and if the hull is grounded to the battery (which I'm sure it is) you should get a full voltage reading of at least 12 volts! Reconnect (carefully) the + (positive) cable that you have disconnected, tighten and you should be good to go!!

In a nutshell, it sounds as if you really don't have a problem at all and that the boat hull/frame is properly grounded to the battery. If you'd gotten no sparks at all when you made the accidental contact it would indicate the hull isn't grounded. On the other hand, if you'd been working on the - (negative/minus) battery post terminal when you made contact to the compartment door, you have a hot wire somewhere touching the frame/hull of the boat and need to do some immediate investigative work!

[ankorklankor]

Originally Posted by KevinP

I have been fortunate to find answers to my questions with a quick search but I am looking for some help on this one. I was replacing my battery terminals and my wrench touched the compartment door, which is aluminum, and gave a pretty good spark show. Should the hull be grounded or is there a issue with the wiring? The boat is a 2002 Pro V, thanks.

When disconnecting the battery on any vehicle always disconnect the negative post first then the positive post and conversely when connecting the battery always connect the positive terminal first followed by the negative terminal.

Following this procedure with the negative terminal disconnected if your wrench touches the vehicle (boat, car, etc) while connecting the positive terminal the circuit is incomplete and the arching and sparking will be avoided.

David.

[KevinP]

Thanks for the quick responses, I just checked and everything seems to be good. I was doing the pos. terminal, I checked it with the voltmeter and there is nothing on the neg. side. Just wanted to make sure that was normal, getting the boat ready for the water tomorrow.

[perchjerker]

bottom line is always, always, always, disconnect the negative battery terminal first and connect it last!

No matter what type of vehicle you are working on, car, boat, tractor, etc.

unless it has a positive ground like some old british cars had