1988 thunderbird Instrument Cluster

I am trying to swap out my current instrument cluster on my 1988 thunderbird. It is the digital speedometer and i am trying to swap that out for this digital speedometer with the digital tachometer as well, however the tachometer does not light up or anything, and neither does the gas gauge that is under the tachometer. And when the new dash is plugged correctly is it very dull, but all the lights have been replaced so its not the lights in the cluster. I need help. Anybody have any idea of what to do?