[bigfish95971]

Does the water come past the door seal?

 

[bigfish95971]

Thrd light is a possibility, but there should be something in back too, loose door or window seal and hard wind blowing is good possibility. Fix the door latch.

 

[bigfish95971]

Couple of things. if the back door is loose, the front door is loose. Water does flow down hill to the front. If you have a gasket for the light install it. Obviously the lower part of the door seal is damaged, how is the top?
I would bet on wind and hard rain came in around the seal due to loose door latches, or maybe you left a widow down a bit. Hard wind and rain will push water through any loose or bad seal.

 

[bigfish95971]

Any rust through the floorboard? Any deep water fording?

 

[bigfish95971]

My mistake, What is a "sliding door"?

"the latch on my sliding door is also broke?

Where do you live?

 

[bigfish95971]

Either one or both. We call the "sliding rear window" not a door. I suppose the latch is broken? Try an auto glass shop and see if they can get and install a new latch. Or jerry rig something your self. Put in the light gasket and add a light coat of silicone if you like.