Take a look at this link, I think it may help;
There are two main points, considering the way the law is worded, that I believe are in our favor (I am an AZ student as well)
(1) The law is very clearly designed to prevent almost any property owner within AZ from denying a person's right within their own vehicle.
(2) The law has specifically outlined what types of properties/locations that this law does not apply to. College campuses of ANY KIND are not mentioned in these exceptions.
PS There is no language in this law regarding the status of the weapon; whether loaded or unloaded, as far as I am aware.