Cabin fan runs even when main switches are OFF

[aa331]

Today I replaced the cabin spotlight with a small fan. Install went great. The problem came when I turned OFF both of the main switches (2 batteries, 2 switches), and noticed the fan keeps running, much slower, but it's still running.

Any ideas why that would happen? Doesn't seem right. Do I have a bad battery switch (Perko), bilge pump switch, or what?

Thanks, Alex

 

[no problem]

If there are other wires on the hot side of either battery, remove them 1 at a time until the fan stops. That should give you an idea where to start looking. Good luck with it.