Voltage issue found

[Lite Tackle]

12.8 volts at battery, 11.9V at helm accessory fuse block. Found the 40A breaker in battery compartment corroded beyond cleaning. #6 wires not tinned and a bit of corrosion showing in the wires too. Replacing both ASAP.

 

[seasick]

Non tinned wires are not something to be concerned about. I do need to know more about what and how you measured the voltage. Did you use a voltmeter at the battery terminals?
Where did you measure the 11.9 volts and to what reference (ground point)? What was powered up. If there is no load, there will be no voltage drop ( OK there is a very very small chance of a current drain in the actual wiring or bus bar)drain somewhere .
I assume you measured the voltage at the helm. Is that true? Remember you can have a drain on the ground wiring due to excessive resistance as easily as the hot side (12 volts). That is easy to check.

Assuming something is drawing current, measure again and then turn off everything, radio stereo , ignition, lights, GPS, sonar, whatever to see when the voltage comes back up. I like these problems, they are usually easy to find (and hopefully fix).

 

[Lite Tackle]

Fluke 87 volt meter used. Nothing powered up. Battery switch on, 1. DC voltage checked at battery 1 posts and at subpanel at helm (other end of leads from battery). The voltage drop, and there always will be, was excessive. Corroded terminals on back of 40A breaker and wires are the culprit. Replacing breaker with high end Blue Sea unit and replacing #6 with Ancor wire to fix problem. Replaced sub panels, wiring and lugs previously. Pictures of old breaker and wiring as well as replacement parts pending.

 

[Lite Tackle]

20yo non tinned wires on a saltwater fishing boat very well could be a problem And in my case are causing a high resistance dropping my voltage.

 

[seasick]

Grady historically has not used tinned wires. I don't think that is an issue per se.

Regarding the voltage drop: If there is no load, there can't normally be any voltage drop. If indeed there is a voltage drop and nothing is powered up, than there is some sort of current path to ground. A saly water corroded fuel block can do that but it is uncommon.

 

[Lite Tackle]

My mistake, I was working when I was posting (or should have been). There was something drawing current. Not now since I cut out the breaker and lugs for replacement. Hopefully this will resolve my issue. But, based on your response, I will still have something drawing current with supposedly everything powered down.

 

[SkunkBoat]

Regarding the voltage drop: If there is no load, there can't normally be any voltage drop. If indeed there is a voltage drop and nothing is powered up, than there is some sort of current path to ground. A saly water corroded fuel block can do that but it is uncommon.

can't measure anything without changing it....

 

[Lite Tackle]

This is coming out. Tried to clean it up with contact cleaner and wire brush. Made a decision that 20 years was long enough.


This is taking its place.

 

[SkunkBoat]

Yep, I had to replace mine after we "went dark" at night on our first canyon trip. Did the same replaced with one that also acts as a switch and doesnt hide the connections.
If you have one of those OEM Grady 40A push buttons on your boat you should change it NOW.....

 

[Holokai]

This is coming out. Tried to clean it up with contact cleaner and wire brush. Made a decision that 20 years was long enough.
View attachment 13067
View attachment 13065View attachment 13065
This is taking its place.
View attachment 13069

Exact same replacement I did. Didn’t even bother wasting contact cleaner on it. Check all the terminations and protect them with dielectric grease or the like. Glad you found what should be the culprit. Let us know how it turns out.

 

[wrxhoon]

I replaced mine in my old boat with the same one as above. She was still perfect when I sold the boat.
When I got my new to me 2013 seafarer the first thing I did was to check the red button breaker, she was still like new to my surprise so I left it alone.
I think the first sign of failure is rust mark under the breaker, if you see that replace asap.

 

[seasick]

can't measure anything without changing it....

That sure sounds like a reference to the Heisenberg uncertainty principle Perhaps a new clue to your background

 

[Lite Tackle]

can't measure anything without changing it....

The boat will be at the shop long before reaching atomic level of troubleshooting.

 

[SkunkBoat]

That sure sounds like a reference to the Heisenberg uncertainty principle Perhaps a new clue to your background

no uncertainty at all. The voltage you measure is the voltage with the meter in the circuit.

 

[Fishtales]

classic GW wiring....

 

[Summertop511]

Now I’m checking behind mine tomorrow

 

[Lite Tackle]

Swapped breaker this morning, 12.7V at battery and 12.5V at helm sub-panel. Looks like my work was a success. Sometimes it’s better to not overthink things.

 

[seasick]

I see that you have three in-line fuses back there. One is for the auto bilge aft pump. If you have a mid ship auto bilge pump, one would be for that. What is the third one powering?

 

[seasick]

Just curious; What was powered up when you measure a 0.2 volt drop from the battery to the acc bus

 

[Lite Tackle]

I see that you have three in-line fuses back there. One is for the auto bilge aft pump. If you have a mid ship auto bilge pump, one would be for that. What is the third one powering?

5A brown/red - auto float switch forward
5A brown/white - auto float switch aft
10A red/pink - memory wire