OK everybody, after waiting for the team to select and order the gauges, finally getting the information out of the vendor, conducting a fair amount of research into OpAmps, and playing around with an Uno and a pot, I think I have a slightly better understanding of how the input side of my little project is going to work. The signal from the majority of the sending units is .5-4.5v, which is great as I won't have to screw around with dropping 12v signals to Arduino levels. If my understanding of the OpAmp is correct, I need a simple voltage follower as arduinoadrian originally recommended. My question now is, can somebody recommend an OpAmp that will fill this need?
Also, any input on what would be the best way to take the 0-12v signal from the voltmeter, and bring it into the Arduino? I've read that I am probably looking at a voltage divider, but any other suggestions (including links to reading material) would be appreciated.
I'm still waiting on info for the tach and speedo, and will tackle them when it arrives.
thx,
bfj