hardwiring a remote

If I were to want to hardwire that identical remote (alpine RUE-4202) into my electrical system so I never needed to get back in there with batteries, what sort of resistor would I need? I realize this is not an electrical category, but I figured it would be best to post in the same area as the original post. I am also sure I will get a lot of guys grumpily telling me to go learn my ohm's law... but my problem is this. I don't have access to either the remote right now and don't know what voltage it needs or what kind of internal resistance it offers. Can anyone help me out? Thanks in advance.