Wired right in without any trouble. Open the top of the unit for access to a multi-position dip switch and three trim pots. The dip switches select set/run and trip direction (rising / falling). The electronics are potted in epoxy.
I've got mine wired to
oil pressure, water temperature, and the gas gauge. I've tied the two critical outputs together to a bright red light and the much less critical gas gauge output to an orange light.
The thing works like a champ.
Oil pressure before engine start causes the red light to come on. Gas sloshing in the tank causes the orange light to come on (I've really got to get in there and re-adjust the gas gauge setting). I've got the water temp set to 210 degrees and the red light flashed one time in 30 minutes of stop-n-go.
Well worth the cost (and this from someone who could have just cobbled up one from scratch in a weekend).