I am looking for help!

I am trying to help a friend of mine fix his 1996 Sedan De Ville.
His wife went over a bump a couple of weeks ago and his digital dash went dark.
Now the speedometer is blank however with just the key on, not running, the normal lights appear on the upper part of the dash. As soon as the engine starts, there is nothing.

Now on top of this problem, when he open the car with remote or turns the key on, the trunk opens and the gas door opens.

Have not found any fuses blown or bad relays and the problem persists.

Need help or at least a direction to follow. Have been told that it might be a cable but don't have any idea which one.

Any advice would be greatly appreciated other than going to dealer.

Thnaks