184 MA draw on main battery cable

[tgisinger]

Put my meter in line on the main cable going to the starter and it is showing a draw of 184 ma. Anyone have an idea where I need to be looking? My background is industrial maintenance, never worked on a boat.

 

[alldodge]

Would help to know what size boat we're discussing. If its a bass boat or a large cruiser

Assuming the boat doesn't have a Battery switch, or its not turned OFF

That small amount it might be a stereo with keep alive, stereo amp, a leaking alternator.

 

[Chris1956]

Some Mercruisers have repressed current systems to protect against galvanic corrosion. These use some small current when boat is moored.

 

[tgisinger]

Sorry about that, it is a sea ray 230 with a 5.7 bravo 1 mercruiser. it has the mercathode system.

 

[alldodge]

As Chris and you mentioned, the Mercathode (repressed current system) could do it, more so if sitting in the water

 

[tgisinger]

I have not put the boat in the water yet and it will not be left in the water, have a place at the lake so we will be loading after use daily. I just bought it and was checking out the electrical system, battery was dead to the point it would not even click the starter. I installed a new battery with a tender. I will not take it out until I finish checking the electrical and cooling systems. I saw where somebody had done some "customizing" on the trim pump wiring, down works on the switch but up only works with the trailering button, other than that I think it has a bad tach.

 

[alldodge]

Could disconnect the mercathode so long as it isn't connected to shore power in the water for long time

Could also install a Battery switch

 

[tgisinger]

Thanks for the help, probably going to do the switch.

 

[440roadrunner]

Maybe I'm stating the obvious -- have you isolated it? Pull fuses until the drain goes away, and if that does not kill it, look for whatever is full time connected. Even alternators can leak (diodes usually) Dirty water might cause a leak that big AKA minerals, salt, whatever, in the water makes it conductive. Don't make assumptions and check ANYTHING connected. Switches can leak if they get dirt and moisture inside.

 

[Chris1956]

Those Mercruiser PTT systems have a trim limit switch. They are open to the water, and therefore rot out. So repair the switch, if even possible, get used to using the trailer button to trim up, or wire the trailer button to the trim up switch...your choice.