where can i get DIAMOND DA-20 for FSX add-on?

i downloaded and installed the Diamond add-on on this website but the gauges will not load up. anyone have the updated version for fsx

Without a link to it I don't know what the exact problem can be.
If it was for FS9 not FSX the gauges won't work anyway.
If it was a FSX then in the read-me accompanying the aircraft it should state where the gauges go...possibly into the main gauge folder and not stay with the aircraft in the simobjects/aircraft folder.

Try that and or post the link to the aircraft, an exact zip file name would help also.