How do i know if the Mercathode system is working?

[gkm24]

My Mercruiser 130 2004 has a Mercathode system fitted. The boat was kept in a fresh water environment but is now stored on a trailer and used in salt water.
Even when I picked up the boat, I noticed a lot of corrosion on the outdrive. I think that the previous owner kept the boat in salt water.
I know that it is not so important now but how would I check that the system is working?

 

[tpenfield]

There is a test procedure that you can do. . .

http://www.mercstuff.com/mercathodetest.htm

 

[alldodge]

The probe used is platinum coated copper wire wrapped around a plastic stick. Bought one some years back because I was having trouble with corrosion. If your boat is not plugged into shore power, I would suggest make sure everything under the water has a good coat of paint on it, this includes the props,

 

[Bondo]

Ayuh,.... Welcome Aboard,.... To go along with what AD is sayin',....

Makin' SURE the Bondin' System is up to snuff is just as important,.....

All those little strap lookin' wires on the transom, drive, 'n motor have to make electrical connection to the hull's ground, usually the motor's block,....
Same as the green wire on the gas tank, 'n fuel fill fittin',...
It's a Bondin' wire, not so much a Ground wire,...
Same thing, only very different reasons,....

All metal parts exposed to the water has to be Bonded to every other metal part on the hull, exposed to the water,.....