Hiya and welcome! A few ideas which might help:
1) I'd recommend siting the tank away from direct sunlight. Even through a shaded window, there can be heat spikes which could be dangerous to the Corn.
2) Those strip-type and dial thermometers like the ones you have fixed to the back wall, are very inaccurate. I've seen one of the dial ones 20 degrees out. I'd recommend buying a digital or infra-red one as soon as you can afford it. A Corn's safe maximum is a lot lower than you might imagine at 90 degrees (aiming for 85 on the warm side floor would be ideal), so it's important to know the correct temp.
3) You need to be measuring the temp on the floor, as that's where the Corn will be. If you measure the air temp part way up the tank wall as with your current setup, the snake could be experiencing very different temps than your thermometer registers. Ambient air temp is a bit of a red herring as the snake isn't up there. Plus if you use an undertank heater (heat mat or UTH) then those are designed to heat the floor surface and not the air in the tank. Ideal for a Corn, but needs to be monitored and controlled at the hottest point which will be the floor. The thermometer needs to be in the same place as your thermostat probe.
4) Corns are naturally very secretive and there are a lot of wide open spaces in your tank. If you can find a few more hides to put in there, your snake will be inclined to move about more. Strangely, the more things you give it to hide inside, under or behind, the more likely you are to see it out and about! Plastic foliage makes good ground cover and looks great
5) I don't know the constituent chemicals, but I'd be careful not to use the Armor-All near the tank. Snakes are very sensitive to everyday chemicals which wouldn't cause a problem for most pets. Even things like air fresheners, plug-ins, perfume and furniture polish have been known to cause issues.
Hope that helps.
Good luck with your new snake! We love plenty of pics of new arrivals after they've settled in!
Yup, trying to get him more furnished with plants just kinda doing it a few weeks at a time. My local pet store is very limited, and I kind of have to order things as I think of them. Any ideas on what type of plastic plants to use; Vines, Branches, ETC? I havn't seen him having any problems with coming out and looking at me.
I have a temp gun that i take his temps with periodically and his UTH Is Hooked up to an Digital thermostat, the probe is glued to the glass inside on top of the Heat mat.
As for the armor all. I just got in from cleaning out my van and kinda set it there when i took that picture. However if you want to see my guy sometime I'm sure i could post one on Photo bucket
If you have a dollar store nearby they're a great place to get fake foliage. I got a fake ivy vine from there, cut it the size I wanted and lined the floor in the front of the viv with it and sort of draped it up around stuff too. Sometimes you can find great fake plants. Corns love toilet paper/paper towel tubes too, not the most attractive in a viv but I sort of bury our's in the aspen with only the openings showing. I wish one of our stores would carry the colored aspen.