I just reassembled my dash. It would be easier to mount the pad first as some of those nuts are hard to get to with the instruments in the way IMHO.
I used an old blanket to lay my new dash cover (cap) on.
Secondly, I would make sure the main bezel frame has a good ground to the dash frame. If a bulb has a metal housing/plug, chances are it relies on a ground. So if that metal bulb connector attaches to a metal frame anywhere. Make sure that metal frame is grounded.
I also made an extra ground from the dash frame to the body frame because the interior was completely repainted.
For dash assembly, make sure to install the heart-A/C controls first, then the control panel to the left, then the main bezel assy, then the light bar. In that exact order. It is a puzzle in an order. But very easy.
Then the plastic trim attaches below.
I learned the hard way.