I have had the same problem about two months ago. During a heavy rain storm my cars factory installed alarm horn suddenly went off and would not shut off, and I was driving. It really sucked. I pulled over and popped the truck and disconnected the alarm horn. But my lights would not shut off. I brought it to my dealership they told me there was a water leak in the passenger side fire wall and it shorted out my security module that is located in the kick panel. My cars an ’06.

Definitely guys keep an eye on your carpet pads.

 

ive had my car since they came out in 05 and ive drven in heavy rain about 30,000 miles
i have never seen water in the pass side but i wonder if i should remove the kick pannel next time it rains just to check