Oil Pressure System monitor sensor location?

[ROTYDE]

I have a 1996 330 Sundancer with twin 7.4L mercs shaft drives. What sensor or sending unit controls the oil pressure warning light on the system monitor panel on the dash? Does it operate off of the oil pressure sending unit or does it have a separate senor in the block somewhere?

 

[Bill Curtis]

There is a separate pressure switch on port side of the block where the filter goes. The one on the back / top of the block behind dist is pressure sender.

The alarm is just a pressure "switch". The gauge sender is a variable resistance "sender".

For the life of me, I don't know why they didn't just put a "T" in the top one and run both the sender and the switch to it. I guess to save the HUGE expense of adding a "t" and just putting it in an existing hole.