You are correct about the lights. One is high temp and the other is low oil. I installed another alarm which has an audio alarm if temp goes up or oil pressure drops. I wired it to the key by wiring into the fuel pressure pump which comes on when key is turned on. It is a little annoying to have the alarm come on while holding in the glow plug for 15 or 20 seconds prior to start, but chances are I would notice the alarm before I would notice the light coming on. I think it was about 30 dollars and took about an hour to install.