i have fitted oil temp,oil pressure and boost pressure gauges the smoke type ones.

they have a red ignition wire,black earth and orange dash illumination wire.
i have wired them up as it says and they come on with ignition and are illuminated,so does anyone know what the point of having the wire for illumination is? as it does not seem to do anything when light switch is operated
as long as the ignition is on they are powered up and illuminated

 

have you wired them upto your light switch cause mine dont come on till i turn my lights on if so have you got your red and orange wires the right way round

 

yes all wired correctly they come on as they should when ignition is switched on,it is just operating the lights does not do anything to the gauges even though the orange wire is connected to illumination wire on car