Ahh, the bane of P2 owners. Got me last week.
$271 bucks at the usual shops, bit more at the dealer. Plus ten plastic rivets and one oddball screw. And more work than it should be. Grrrrrr.
But, since I'm a firm believer that no one is ever going to steal a Volvo, let alone a 16 YO S80, I'm contemplating just pulling the fuse. Guess I'll get a message and maybe the sunroof will never work again, but I can live with those.
But.....
Is it that simple or will some other subsystem suddenly pitch a fit someday in the future because it can't talk to the alarm?
Thanks

 

Pulling the fuse won't stop canbus interference (corroded battery damages siren module circuit board, then sunroof does not work) Possibly simply unplugging the Siren module will stop the interference. (never tried it but seems logical) Next in line is the UEM - that controls your remote lock/unlock functions -

 

Thanks hoonk, I suspected as much. By the time I work my way to the plug I may as well replace it.
Thinking about a salvaged unit and replacing the batteries, I thought about making a remote battery pack in the engine compartment but on second thought if the batteries lasted 16 years I don't think see myself having the car that long.