HarleyTechTalk

Anybody take a 5 volt analog and step it up to 12 volts for a 12 volt analog gauge?  I have an oil temp gauge I would like to repurpose.  It goes from 130-350f.

I'm not 100% sure I know what your trying to do.
Where is your 5v source coming from ?
Is it from a sensor ?
I don't think it is as easy as a 5-12 converter.
I would expect the 12v gauge would normally be using a variable resistance sensor .

As a matter of interest, I use a self powered meter fitted to the rear head
CHT sensor mounting hole (carb bike) :-

https://www.revzilla.com/dirt-bike/trail-tech-tto-temperature-meter-spark-plug-sensor-surface-mount

Just search for 5-12 VDC converter modules. There are lots on Amazon and elsewhere.