Gauge cluster swap 74 to 75

I'm swapping my cluster out of my 75 maverick and installing a 74 maverick's cluster in it's place.

I disconnected and installed the 74 last night and cranked the car.

The fuel gauge worked, but that was it. No lights.

What do I need to do? The 74 printed circuit is in excellent condition and the bulbs looked fine when I inspected them.

 

Have you rechecked the plug to see if it worked it's way out a bit when you put the cluster in?

 

Per 1bad6 the clusters are same, check connector and traces to be sure they are making contact...

 

Perhaps you have a very late produced 75 that possibly could have come with the 76-77 backplate????
Was the backplate in your 75 white and you are now installing the bluish green backed cluster?

 

The cluster is fine, they are both bluish green.

The bulbs were good, it was the actual insert's that needed to be cleaned. They where slightly corroded.