Alarm sounding off randomly...water under passenger floor

[gobies]

Alarm is sounding off randomly, locked or unlocked. Recently had several gallons of water under passenger side floor. Removed amp under seat, then shop-vacuumed under the carpet to remove water. Unsure of water source, possibly front cowl/windshield. A-pillar sunroof drain elbows clear. what could water have shorted under floor to activate alarm? Could alarm battery leak cause erratic alarm firing?

Manual shows alarm fuse in position 8 in the driver's side dash fuse box. That position is blank/empty in my fuse box. Where is fuse for alarm?
Alarm is going off every 5-10 minutes. How can I shut off alarm, short of disconnecting battery?

[gobies]

Okay, I think alarm problem was unrelated to the moisture. (I've yet to check the alarm battery).
On the night I posted, I went back outside, opened driver's door so the alarm wouldn't reset, & left driver's door unlocked.
Key fob seemed a bit unresponsive. Found the other key and remote, noticed it operated more smoothly. Took both apart for cleaning, expecially the buttons and rubber membrane. No more alarms at 15-20 minute intervals.
Doubting the simplicity of this fix and still suspecting the moisture under the floor was part of the problem; after sunrise, I retrieved the shop vacuum, adapted down from 2.5" hose to 1.25" hose and crevice tool, and slid them into the amp mounting hole. With some body english and profane mumbling, I maneuvered the vacuum hose and crevice tool under the "sub-floor" and through most of the passenger side foot-well area. I could tell by the sound that the vacuum was picking up some moisture, but judging by the vacuum tub, it was only a couple of ounces.
Next, I set up a dehumidifier in the cargo area and ran it in the closed car for a day, pulling another 10-12 ounces of water from wherever it was.
A 200 gram size box of silica gel dessicant (with humidity indicating strip) will fit under the amp, in the subfloor. Changed it out 3 or 4 times over a couple of days, until the humidity strip indicated no change ( under 20% humidity). Checked again today, no change
Proactively, I'm going to trim a few ultra absorbent disposable diapers and slide them under.
Diapers will hold a couple of pounds of "fluid".

[oragex]

Also check the drain tube at the bottom of the cabin blower. The front footwell carpet can be removed for drying by removing the two seat rails bolts and bending the seat a little backwards.