1995 Bass Tracker with 40 hp mariner

[parristb]

With the wiring harness disconnected at the motor & the other end disconnected under the console. From engine ground to boat ground I have 4.8 volts DC on the meter. This can't be right. Any help? The boat has no spark - I'm sure my black box is fried because there is 4.8 volts DC on the kill wire also.

 

[Don S]

Re: 1995 Bass Tracker with 40 hp mariner

ALL grounds need to end up hooked together and terminate at the Negative terminal of the battery.

Without knowing where you had your test leads to measure this 4.8V, it's tough to say what you measured, or why you get 4.8 on both tests.

 

[parristb]

Re: 1995 Bass Tracker with 40 hp mariner

ALL grounds need to end up hooked together and terminate at the Negative terminal of the battery.

Without knowing where you had your test leads to measure this 4.8V, it's tough to say what you measured, or why you get 4.8 on both tests.

Don, I measured this from 1 of the mounting screws of the switch box to the aluminum part of the forward console. But, I also went from different "grounding" screws on the motor to the same point at the console with the same results.

 

[Don S]

Re: 1995 Bass Tracker with 40 hp mariner

I measured this from 1 of the mounting screws of the switch box to the aluminum part of the forward console.

Do you know how to use a multi-meter? You sure your not reading ohms instead of volts? No way should you read 4.8 volts where you measured.

 

[Silvertip]

Re: 1995 Bass Tracker with 40 hp mariner

If you are trying to measure anything using the metal parts of the boat for ground -- give it up. The hull or metal fittings on a boat are not ground. ONLY the negative terminal of the battery is the ultimate ground. Everything ground on the boat ultimately winds up there. Yes the engine block is also ground because the large battery cable is connect to it and the negative terminal of the battery. Since the engine is bolted to the hull that makes the hull ground but not a very good one. Not good enough to be grounding electrical devices to. The ground buss on a fuse or breaker panel gets connected to the negative terminal of the battery as well via a separate # 8 or 10 gauge wire in the BOAT harness. So as Don says -- are you sure you know what you are looking for? The engine harness doesn't even need to be connected to run a magneto ignition engine. The battery just spins the starter. The ignition is not powered by the battery -- it powered by the stator under the flywheel. So chasing a problem at the helm won't solve a no-spark problem if you have the harness disconnected at the engine.