OK...I'm wrapping up on my new guages and sending units installation on my 502(gen VI) when I notice a sending unit I hadn't seen before. I replaced the Oil sending unit (lower port side of engine), the Oil Temp sending unit (remote oil filter) and the water temp and water pressure sending units. I need help indentifying a sending unit at the back of the engine just ahead of the bellhousing on the port side of the engine. It has a white/lite blue strip wire going to it. I'm hoping someone can tell me what this one goes to. Any help is appreciated.

Is it mounted right next to the oil pressure sender? Oil pressure switch I believe. Is it the same color wire as the water temperature sender? Senses low oil pressure and will sound an alarm (if it is what I'm thinking your referring to). Randy

Thanks for the input Busted...I took a couple of pics of the senders to help explain there locations. The one on the oil cleaner mount is (I think) supposed to go to the oil temp gauge (Brown with white strip wire). The other is the one that's confusing me. Its located just behind/below the back of the intake that would be where the bellhousing would bolt to on a car engine...(I don't know the name for what covers the flywheel on a boat)...and has a white with light blue wire. The oil pressure sender on the lower port side below the spark plugs has a green wire. So after looking at the pic...what do you think my mystery sender goes to? Thanks again!

the one by the filter looks to be oil temp, the other is for a warning buzzer/light

Yep, and I think that is tan/blue. Randy

The one under the coil with the tan and lt blue stripe is the oil pressure sending unit or it could go to a buzzer to warn you about low oil pressure...the tiny one in the oil filter housing is a oil temp sender..
if you ground the sender wires it will spike the gauge and it wont hurt anything if you use a standard single light test light..

OK...I think I've got it now. Thnks to all of you for your help.

the one under the coil is the oil pressure alarm ....I bet there is another one on the block on the port side by the remote adapter for the oil filter..... that is for oil pressure .....m

Thanks Mike...the "mystery" sender is the low pressure alarm. I may have caused some confusion by talking about the other senders instead of just asking about the one in question. Now I just need to find the corresponding wire at the dash. Thanks for your iput. jim