Have 290 SeaRay w twin MERC That have corrosion prob. How to trouble shoot mercathod

[toddschubert]

I'm from the Johnsonrude forum but I'm helping a friend w 290 Sea Ray that has badly corroded od's. We are pulling them today to further inspect.
Could someone briefly explain the mercathode system and how to trouble shoot if it is working properly?
Owner thinks neighbors boat is putting current into water exacerbating the problem.
How can I prove that?

 

[toddschubert]

Re: Have 290 SeaRay w twin MERC That have corrosion prob. How to trouble shoot merca

model numbers and pics to follow