I recently changed all the guages in our 91 twin 454 Nova ST.
There is a white wire that is in the harness and it obviously is not hooked to anything. There was another white wire jumpered to the blue panel light wiring. Anyone know what a white wir is used for in a scarab harness? Thanks

in my scarab it is the anchor light circuit; however if it is jumpered to to yourblue wire instrument panel lighting is may be for compass light or the trim/drive indicator panel light. hope this helps. jeff

Do a site search for Mercruser wiring.. there has been the whole color coded diagrams posted in the tech section..they are all pretty standard...

white is usually panel lighting for guages!

Scarab used white for docking lights. Should be a 14 or 12 gauge (slightly thicker than the rest)