2005 Chevy Suburban Gone crazy!

My 05 Suburban has gone completely nuts! This morning I started the car to find many of the electrical items were not functioning at all or not functioning correctly. For example, when running, most guages dont work, all dome and reading lights are on, only the rear windows roll down, the AC doesnt work, etc. However, some of these items seem to function when the vehicle is not running but the key is in the accesory mode. I have a code reader but it is not much help and claims that the ignition is not in the "run" position when in fact it is. So no help there. There is a posibility of rodent activity although I see no visible signs. I do however live in the country and just last week suffered some rodent related damage to my 08 Tundra. Any advise?