Jeep was sitting over the weekend in the rain, facing slightly downhill. Got in today to go to work and saw a bunch of water pooled in both front floorpans. Didn't notice any moisture under or behind the front seats, so I think it was coming from the dash area somewhere.

Any ideas on where to look for the leak?

 

Try checking the fresh air intake sometimes theyll leak there

 

I'll add that to the list! From reading around since posting I also saw some people saying door seals, roof rack holes, antenna hole, windshield seal, and something about the fuse box.

Fresh air intake seems more likely to me, although I'm not sure how it would get to the driver's side.

 

Does yours have a roof rack? Sometimes the plastic grommet comes loose above the driver's head and water in a hard rain or windy day can get into the hole and leak down above the door frame. It's especially worse if the driver's side is slightly leaning downhill so the water runs (pools) towards the driver's side and runs across the hole (grommet).

 

I think I found it. The two corners where the outer windshield seals meet the upper seal were in pretty bad shape and water could definitely get in through there. Seems strange that both would fail at the same time, but there was also a lot of debris at the base of the windshield under the plastic piece beneath the wipers, so maybe those two things compounded to flood that entire area.

Regardless, I put some silicone sealant on the corners. Will see what happens with some thunderstorms tomorrow!

 

Leaks with water near the floor potentially comes from the lower bottom side of the door where it closes. There should be a seal around the entire door including the bottom of the door. This is an area that has caused problems for some Grand Cherokee owners. Other areas , AC drain plug, Sun roofs have drain tubes inside the corners along each side of the windshield (on the inside) that become brittle and crack.

Here's a video that explains leak problems around the door.