This morning, during a period of not too heavy rain, my factory alarm started going off. I went to check, thinking maybe a branch had fallen on the truck, or something like that. Nothing was discovered; no signs of forced entry or anything else. I reset the system and five minutes later, it went off again. This is the only apparent electrical malfunction I've had with this truck. Any ideas? I though maybe some rain got where it wasn't supposed to, but it wasn't raining that hard. The truck's been through much more than this little downpour. What's up?