Yet Another CCM/Alarm Cry for HELP!!

[EdF]

I've a 2000 model V6 Tdi and in '04 it had the CCM/alarm & bootlid catch alarm faults which cost me £400 at the main dealer to get fixed. Now it's happened again. Design fault, or what?! Both occurred after the car hadn't been used for a bit and during a heavy frost. I can start the car okay but of course the alarm is doing weird things. The carpets don't feel damp, but there's a little water below the battery. Apart from clearing the drain holes I don't really know where to start. I don't have access to the VAG-COM, which I believe is the magic box which gives fault read-out's, so I can only guess I can try and search for corroded terminals and the like.. As we are about to sell the car, I don't really want to spend another £400+ on it, but is there no option but to go to the main dealer? If someone can give me a few pointers as to where to look and what to do, I'd be very appreciative. THANKS!!