What is the computer in front and how do I get that working?
Is the rest of the wiring from the red plug necessary? I have one of the legacy passenger side sun visor mirrors I just wired up but it's not part of the wiring configuration that you see on the late model Jeeps. What do I need other than the mounting bracket?
I did not wire in the computer. I believe the part that is in the console is just the display, fed by a computer someplace else in the car. I believe you can see things such as fuel economy, distance to empty, etc, on the display which are probably based off digital feeds from the fuel guage, speedometer, etc, all of which are absent in Eagles. I took the display out and have been considering what I want to put in its place, but haven't decided on anything yet.
I did not use the mounting bracket from the Grand Cherokee. There is a hole for a screw in the front, which lines up nicely with a hole that was already in the Eagle, underneath the middle piece of the windshield trim. If you want a really good fit, you should trim the tube for the screw. You can also trim the console itself so it fits better, but that will require you to re-cover the console. On the back end, I originally fabricated a bracket that went over the cross piece of the console which happened to line up well with the Eagle dome light so there was a spot to screw it in. The upholstery guy who actually did the installation riveted a cross piece in the right spot and screwed that in the dome light screw holes. The rear insert part of the console was originally screwed into the main console piece from the top. In order to install it in the Eagle, you have to pop the insert in after you screw the main console in at the dome light location. However the insert pops into place very securely, and can be removed if you need to take out the console, work on the wiring, etc.
In terms of the wiring, you can get a positive feed and a switched ground feed from the current overhead light in the Eagle. Then you just need to run an un-switched ground so you'll be able to turn the lights on whenever you want to. I didn't write down the exact wiring but its not too hard to figure out. On my console there were four wires associated with the lights (if I recall correctly) - black, yellow, grey and pink. You don't need any of the other wires. If I get a chance I'll look at the spare console I have and try to figure out what goes where. Good luck!