Silencer alarm system uninstall
So what it turned out being was that the fan relay was bad and shorting out. I couldn't detect that particular short before while pulling fuses because the security system had a constant draw.
The people who had this van before me seemed to find it easier to run a hot from one of the ignition wires rather than replacing the relay.
Will be replacing the possibly molten relay very soon.
Thanks for the help everybody!
:cheers: