Electrolysis on thru hulls

[SILENTKNIGHT]

Hello Steve. I had a marine elctrician come to the boat. He used the refrence cell and a meter. I observed that he tested ALL AC & DC . All the thru hulls in the boat all came back within the parameters . He also tested the shore power dock tower.
When he got into the boat he removed the AC & DC panel. He showed me that he found stray voltage on the AC panel coming off the neutral. He did this test with the power off on all braeakers and un pluged from dock power.

He said my " Bat switch is bad"? and needs to be replaced along with the analog Volt meter on the AC panel.

Does this sound like a correct diagnosis? can this be why im having halos around my through hulls?

 

[Steve DAntonio]

"He showed me that he found stray voltage on the AC panel coming off the neutral. He did this test with the power off on all braeakers and un pluged from dock power."

I don't completely understand this, but it may not be the entire story. Stray voltage on the neutral may be implying a connection between neutral and ground aboard, which would be a problem. That's explained here. https://stevedmarineconsulting.com/neutral-to-ground-demystified/ Haloing around bonded hardware is most often caused by over-protection, however, stray AC current can cause this as well. So yes, that's possible.

Does the electrician have an ABYC Corrosion or Electrical Cert?