My 1995 astro dayvan discharges a fully charged battery within a week if left unused?

I`ve had it checked for elec.faults to no avail, no discharge detected.Replaced battery,alternator, both elec.window motors and switches which all broke down within 2 months of each other. Whilst the window switches were disconnected the battery didn`t discharge,am at my wits end,any help would be greatly appreciated,thanks,Al.