Busrider, about a year ago my Alarm was sounding faint. After some debug, i found the water on the drivers side was up so high it was deadening the alarm (shocked it was still working as the horn was in the water). I cleaned the drain like you mentioned and checked the other side for good measure and sure enough it was clogged but with way less water. I had to pull up the box and practically disassembly it to get in there and clean the drains. I couldn't come up with a good way to get in there otherwise. I did speculate you may be able to get at it from the bottom side if you find the right trim under there to remove, but not sure...