wierd gauge issue

[danielwiebe]

myfuel gauge does the wierdest thing when i turn the dash lights on the needle goes to full tank(i wish it was that easy) also the light for it is very dim i checked all the connections any clues. also the black gauge that looks like its a screen on the far right on an 02 21v what is that gauge for it lights up but does nothing is there a sensor i can trace to check it out
thanks
dan

[danielwiebe]

ha after 17 pages of searching realised its a blank gauge. but still anyone have ideas why my fuel ight is dim and why the nav/anch button makes the needle jump to full

[Sharkbit]

A bad ground will make your gauges act up. As you are saying the lights dim on the gauge that makes me even more sure it is a bad ground. I would check all connections and maybe even jumper another ground wire to your gauge and see if that works. If not check the ground on your fuel tank.

Hope this helps