gauges

my oil and temperature gauge don't seem to work. Does anyone know the operating voltage of the gauges. In other words, if i apply 12 Volts where the output of the sensor would be then i would expect a reading of High or Low oil pressure/water temp? I'm looking to start with trouble shooting the guage before i move onto the sensors. This is for a 95 Wrangler with about 115k on it. Thanks in advanced.

I'm not sure on the voltages, but I had a similar problem with my 93 YJ when I got it. my problem turned out to be a bad spot in the printed circit that is on the back side of the guage cluster. the bad spot on mine was in the 12volt power to the guages, I just made a jumper to bypass the bad spot, and the guages have worked fine ever since.