So here is my fix for the door. The first picture is the opening where the nest boxes install. There is one on each side, so you can choose which side you want to put the nesting boxes on. Sorry about the glare from the sun.
Like I said before the cover was pretty cheesy, big air gap all the way around and cheesy latches. I wanted to keep this access available since the tray is a pain in the neck to pull out now that I had to partially cover it for rain. Not to mention they should have put some metal rails in instead of having wood slide on wood. How long is THAT going to work? Probably not long .Especially since the stupid thing had me cussing the first time I tried to slide it in and out.
The 2nd picture is a peice of wood that I cut to fit over the opening, about 1 1/2 over lap on 3 sides and the bottom even with the opening. Only because it tilts outward (picture number #3), I attached the original door to the backside of my new door. You dont necessarily need to do that, I just used it because it was there, without this peice you would just have to screw another little piece of wood on the outside along the bottom to rest the door on.
So now picture number 4 is a couple of pieces of wood I put together, one on each side of the opening that would accept a 1 x 2 going across the door horizontally to hold the cover peice of wood firmly against the side of the coop, kind of like an old fashioned brace they would have going across the inside of a giant door in a castle (?).
Picture number 5 is the peice of wood covering up the hole with the 1 x 2 brace going across it into the peices that I put on either side of the opening.
Hope this makes sense. It took me a while for my bird brain to figure out how to do it, but now I have tons of access to the inside and room enough to add electrical later on.
Oh and there is one picture at the end with a can of water inside is to show how DINKY this stupid thing is!!