Electrical ground on a boat

[Lwarden]

Is it safe to say that all the grounds run together at some point or another? If I check the ignition/engine ground Ill get continuity on the house ground also? or atleast when the perko switch is in the BOTH position? and should they be seprate when the perko switch is in the 1 or 2 position.

 

[NYBo]

The negative battery terminal is the ultimate "ground" point.

 

[Lwarden]

The negative battery terminal is the ultimate "ground" point.

Yes I realize that but do they have to be independent of one and other from battery to battery?

 

[glenn property of pam]

Most boats with a perko style switch have the dc negatives linked together all the time. The cable linking the negatives should be the same size (gauge) as the wire going to the starter motor.

 

[bruceb58]

duplicate post

 

[bruceb58]

Normally, the house and engine ground should be the same. The house and engine grounds are usually tied together at the batteries.

If you have a Perko switch, that is 1/2/both style, you don't have a separate house battery unless you have house loads connected to one of the batteries through another switch or directly tied to that battery.

In addition, it is pointless to have separate grounds for house and engine. Besides the fact that you could potentially have floating voltages between the two, it makes it necessary to keep track of 2 different ground planes when attaching loads.

 

[Bondo]

Ayuh,.... Generally speakin', the perko switch controls only the (+) Positive leg,....