What is needed for this project..I wanna wire in a small LED light to a couple of my guages...(fuel pressure...oil..water..)...I want the LED to light up when pressure falls below a certain psi...are special gauges and or senders needed to do this......or is there a link that can be posted on any of this information as far as whats needed and how to wire gauge...led..and sender together..Thanks

Im assuming your boat has a alarm.
You should be able to wire them into your alarm wire. You would only need one light really, Since everything(Oil,Water and Drive resevoir) reads of that wire. Those are ground wires though.
If you took the LED + to 12 volts then LED grnd to alarm wire should work. Only problem is I think there is only one alarm wire going to helm. So you would have to run wires back to each alarm sending unit if you wanted know which one. Your lights would go off with the alarm sound so not sure how usefull they would be.
Each sending unit just grounds when tripped. Fuel pressure you would have to T in a sending unit.
You might be better off putting in your own sending units that go off at your PSI that you want. Since they make them in different ranges.

thanks..thats what i was looking for

The only thing the alrm will do is go off with high water temp, low oil psi and low drive fluid, unless you have a newer engine.

You best bet is to get some Livorsi redline guages with the built in warning light.

will look at that option also...i could use some new gauges