How To Test a NAV-5 Display Made By SR Instruments

[Cap]

Hi All,

I have a NAV-5 display in my boat. The PO had removed the transducers/transmitters and capped the thru-hulls, but the transducers/transmitters are laying in the bilge still. I know this is old technology, but everything is still in place, and fires up, so I thought I could check it out and see if it works at all. I guess the biggest issue, or question, is can I uncap the thru-hulls and put the transducers/transmitters back in without flooding the bilge? I've heard that some types of thru-hulls allow this and some don't, true or not?

Thanks...Jeff