Originally Posted by MILD THUNDER (Post 3087067)

I been researching this as i have the same gauges with the red lights.

I found a new oil pressure sending unit in the package in my boats cabin. It was a livorsi sending unit. I imagine the previous owner installed these redline gauges, and had a spare sending unit.

I was told there are two sending unit styles used. Standard and vdo. Obviously VDO is for vdo gauges. Some boats came stock with VDO gauges back in the day, so switching to gaffrig gauges caused erratic readings without changing senders. Also the oil pressure sender must be either a 80psi or 100psi relative to the gauge.

This does make sense, although i have not yet tested this advice myself. I doubt gaffrig and livorsi were manufacturing their own sending units with different resistance values.

Best bet though i would say is to call gaffrig or livorsi and ask them. Im sure this is a question they have answered a million times....................

Originally Posted by cubicinches (Post 3087294)

That is correct. The only gauges that use anything other than a stock Mercury sending unit are VDO's.

Originally Posted by theadamv1 (Post 3087205)

ok well called Gaffrig and ordered a sender for 36.00. Asked who actually made the RedLine gauges and the 1st person i spoke with there said that they DID NOT make the redline gauges.... But then the 2nd person i talked too said that they DID make them but no longer do. But had some of them leftover. Of course the one i need (fuel) gauge they dont have any old stock left.....

So anyone needing any redlines may wanna check and see if they have any old stock of what you might need.
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