So i have a 2003 monte carlo ss i bought and the dome light didnt work so i noticed the fuse wasnt in so i put fuse and bam it worked but i got a heavy night of rain and noticed the passenger floor wet so i did some investigating and found it needed a water deflector which i bought but noticed water was getting the passenger side fuse box wet and the lights didnt work so i put a new fuse it which was blown and instantly it popped i tried another and it popped again...any ideas anyone??

 

Just saw you comment about a sun roof drain on another post. I would verify:
- The door closes completely
- The door seal is not damaged/kinked/collapsed
- The window is completely sealed.
- Check the sunroof drain tube is clear on that side and not damages (I believe it travels down the A-pillar, if someone ever removed that pillar piece and damaged the tub, that could be a big issue).

 

Check the cabin air filter , the rubber seal that hold the plastic cover down sometimes comes loose and will let water enter the car.Good luck

 

i did i did have a leak thru air filter but out a water deflector in and it stopped water from coming in