Grey water tank float switch

[MurrayR]

Can someone tell the if the float switch on the grey water tank has normally open or a normally closes contacts.
I thought it would show an empty tank when the circuit was closed but it does not on my 2007 Cali.

Also what have people uses as a replacement sensor?

Many thanks

 

[sidepod]

Is it level or Hi/Lo indication?

I would've thought it would be N/C then the circuit would be constantly monitored for open circuit?

Pod.