Another idea, because I couldn't sleep the other night....
I've been thinking of removing my Subaru Compass Thingy and making a spot for gauges. (So I'll be selling it soon, with all paperwork \ instructions FYI)
I didn't want the normal round gauges in that area so I was looking for something a bit different. Didn't even know what they would monitor. Maybe put several switches there as well. So I found these Digital Thermostats on Ebay and picked up two of them (only $5 each so if they were garbage, no great loss).
They are actually for computers but 12V DC is 12V DC so I was going to use one for my engine compartment temps and another for my cab temps. Yes, I know... Neither is really needed, but.... To be honest, I was hoping to find something like these and use them to monitor water temp, and tranny fluid temp.... But for only $5, I didn't want to rely on them for something that important.
The probe is about 3' long, and in testing, they are VERY RESPONSIVE! The second you hold one the temp starts to rise. They are pretty accurate as well. I haven't set it up right next to my shop thermostat yet, but if they're off, I think it's only a few tenths...
I plan on starting to work on these this weekend. I'll keep you all posted. Maybe add something like this in between them for water temp... If I can find a red one, since all my other lights are red.
Amazon.com: Koso BA024B11 Super Slim Style Thermometer: Automotive