You can put a simple variable resistor in series with the temperature probe. Or you could put a simple voltage regulator circuit on the 12v supply. You could church it up by making the voltage regulator adjustable.
There might be something wrong with the gage or a ground path since most temperature sensing systems are designed to work independent of the input voltage. A wheatsone bridge is normally used. https://en.m.wikipedia.org/wiki/Wheatstone_bridge A simple mistake in the wiring could be the cause too. Typically the gages have a 12v supply, ground, and sense (or D from the picture in the link). If the 12v and D wires attached to the gage were swapped I think you would see the resulting indication which you are having. I'd take some voltage readings at the temperature probe and at the gage. While you're there check the resistances of the ground wire and the sensing wire. Particularly important in this case is the meter usage good practice of checking for no voltage before checking resistance. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Mar 13, 2017 12:14 AM, "Russ & Melody via CnC-List" < [email protected]> wrote: > > Anyone know if Faria temperature gauges have a calibration function on > them? > > I just finished installing a Universal 25 HP (that came out of a Catalina > 30). The previous owner complained of overheat issues. > > Anyhow, running at the dock, in gear for load, the engine comes up to 180 > F (using a non-contact thermometer) and shows 220 F on the gauge. > Immediately on shutdown it drops to 190ish, on restart it goes back to > 220. I can say the difference is due to alternator running voltage 14.7 vs. > shutdown, 13V. > > I cannot find any good information on the web regarding calibration or the > resistance values that can help, although such items are mentioned. > > cheers, Russ > *Sweet *35 mk-1 > Vancouver Island > > _______________________________________________ > > This list is supported by the generous donations of our members. If you > wish to make a contribution to offset our costs, please go to: > https://www.paypal.me/stumurray > > All Contributions are greatly appreciated! > >
_______________________________________________ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
