Ok or not to connect house battery negative to starter battery?-gctid819416

[JThiessen]

I'm slowly sorting through the wiring in my 97 2859. So far I've relocated all but one of the extra wires off the house batteries over to an adjacent fuse panel.

Tonight I opened up the starter battery, and found that the ground from the house set is just run over to the starter negative post, and then one wire runs to the engine block.

Simply speaking, they are both still grounded to the engine block, but I'm wondering if its something that could cause some odd issues.

I dont have any issues with starting power, but I am battling a slew of electrical issues that all seemed to just start recently.

[Bay39]

Connecting Grounds together (House and Starting bank) should not cause any issues because ground is ground. Be more specific on the odd issues and someone with a 2859 might chime in with the solution.

[builderdude]

Negative is negative and technically it'll work as wired , however it is best to run independent negative cables to the negative source. The way it's wired currently: If your starting bank negative cable becomes compromised (bad connection or corrosion etc. ) then your house bank negative will also be compromised.

[2850Bounty]

"builderdude" post=819419 wrote:
Negative is negative and technically it'll work as wired , however it is best to run independent negative cables to the negative source. The way it's wired currently: If your starting bank negative cable becomes compromised (bad connection or corrosion etc. ) then your house bank negative will also be compromised.

[color]blue wrote:
Absolutely correct!

Always run an independent battery bank Negative cable to the "System Negative Common"........ I.E., the engine block!

We call this "redundancy".

[/color]

.

[SomeSailor]

It's more than just redundancy. Part of the reason you're adding extra batteries is to provide more current to those circuits. When you add current along the positive loop of those circuits, you should be planning for equal return path (negative). The best way to do this is a separate ground/negative bus bar where everything can tie together. I always add more ground path than needed. These boats are under-wired when new and with no chassis ground as you'd have on a car, you're only gonna see more problems as you go forward.

[JThiessen]

Thanks for input - that backs up what I was thinking.

You cant see it in the picture, but I mounted a fuse panel off to the right of the house batteries. Negative goes to the batteries - I was also thinking of running that ground straight to the block also.

[2850Bounty]

"Bay39" post=819418 wrote:
Connecting Grounds together (House and Starting bank) should not cause any issues because ground is ground. Be more specific on the odd issues and someone with a 2859 might chime in with the solution.

[color]blue wrote:
I'll assume that you meant to say Negatives together.

As said, each battery bank should see it's own Negative cable running independently to the "System Negative Common" (i.e,, Engine Block).

(but it's your boat...... do as you wish) [/color]

[SomeSailor]

"JThiessen" post=819527 wrote:
I was also thinking of running that ground straight to the block also.

You're on the right track. A buss bar is the best way to tie all those together.

[2850Bounty]

"JThiessen" post=819527 wrote:
.................... I was also thinking of running that Negative straight to the block also.

[color]blue wrote:
Yes..... your heaviest Amp load will be the starter motor, so your main batt bank Negatives will connect directly to the Engine Block (i.e., system negative common).

A remotely located buss bar is a great idea for the lighter loads such as the helm harness Neg, accessory Negs, etc. [/color]

[SomeSailor]

I have buss bars that the 8D connects to (pos and neg) and then the buss bar(s) connect to the block(s) (and all other DC returns).

Buss bars are nice because you always connect / disconnect additional capacity and are not dependent on a single ground connection.