Oil and Gas gauges not reading

[gt2003]

'96 Malibu Echelon, 320 Indmar Monsoon, black (2 inch) Teleflex gauges.  Gas gauge works when it wants to or, since the gas is pretty much always sloshing, just isn't accurate.  Oil gauge doesn't seem to work at all.  I check the oil and obviously gas regularly but would like suggestions on replacing the gauges.  I believe there is an oil pressure sending unit (maybe) that I might need to replace?  How is the gas level measured?  Is that another thing I might need to replace?

I love my older boat but need a few of these things working so I can feel better on open water.  Planning on replacing the hoses too in the off season. 

[gumbus62]

I'm having trouble with all my gauges in my '98 Response.  Thinking my Kysor Medallion brain is fritzing out.

The gas sender is in your gas tank.  They are known to be somewhat unreliable and if I recall correctly there are upgrades available.  My '98 Response varies pretty dramatically depending on speed and direction.  When the gauge reads close to empty constantly I do a visual on the tank directly.  That sounds silly, but I've had so many fuel system problems lately that I always want to have fresh gas and try to burn down close to E.

The oil pressure sender needs a good ground or it will read erratically.  You can find these online or even at a NAPA part store. Indmar pt# 645002...I think.

https://www.bakesonline.com/indmar-oil-pressure-sending-unit-sensor.html

https://www.skidim.com/SENDING-UNIT-OIL-PRESSURE-GM_FORD/productinfo/R020001/

https://www.napaonline.com/p/SME185899