Chassis grounding on pontoon.

[Dirt Cash]

A friend has a pontoon with a red wire run from the + batt. to the chassis near the motor mount.

Is there any reason the boat chassis needs a + ground?

Is there any reason the chassis needs any "ground" connection to the battery, at all?

[redtech]

first this doesn't sound right
is the motor pos or neg ground
what type of boat and motor
in most cases should not have this pos wire going to the chassis
if neg ground this red wire is more wrong
in most cases the chassis is grounded to help prevent electrolysis

[Dirt Cash]

...the motor is neg. ground but I guess that's really the heart of the question.

It's an older toon that's been repowered by a less-than-professional.

My friend said it was blowing many fuses and her brother disconnected this wire to fix the problem.

I would think it needed to be neg grounded at the chassis but I wondered about the electrolysis issue.

[Ike]

It should be negative ground. It was blowing fuses because you had a direct short to ground.

[Dirt Cash]

...it went all last season with the pos ground hooked up!

I figure something (a light, etc.) shorted the neg to chassis and that's whty it started blowing fuses.

I work in electronics and understand the grounding theory in a car, but my real concern was with a possible link to the electrolysis issue.

To simplify the important question: "Is a NEW toon neg grounded to the chassis?"

I think that is the crux of the issue.

[redtech]

dirt cash please don't dig to deep. the toons should not have a pos ground....
this was some what a mistake that got away from a shop
something that is neg is most likely touching the toon now this would not matter if everything was right but unlike cars you don't ground to the chassis and the boat has more none conductive materal than conductive so something like this at time may not be found for years

[Dirt Cash]

So should she neg ground the chassis or leave it ungrounded?

[redtech]

neg ground the chassis and remove that red wire

[Dirt Cash]

Got it! Thanks a lot!