water is entering the vehicle on the drivers side on the floor - My 2006 1500 Vin Z just started having this issue. I pulled the floor mats to clean ...

My 2006 1500 Vin Z just started having this issue. I pulled the floor mats to clean the carpet and the carpet was soaking wet. I left the mat off for a few days and it all dried up. Then we started getting a ton of rain. That said even after raining for almost days straight I hadn't been driving it so when I got in the truck the floor was still dry. However, after the 30 mile drive to work the floor was soaked again. I removed the plastic molding to pull back the carpet and I don't see anything telling. There are no obvious holes or damage to the underside of the vehicle and there is a plug there for a cable or conduit but the integrity appears good. I got the hose out and sprayed water up on the underside of the truck but didn't see anything intruding. The water is coming from the floor, not running down the firewall. The first spot to show the water is right below the hood release on the floor right where the carpet meets the molding that goes around the hood release.

Peel back the carpet and dry the area. Leave the carpet peeled back. Get a nice bright light. Then take your garden hose and start spraying (gently) one small area at a time. Be patient, give the water time to work its way down. Look around to see when/where it leaks.

If you're lucky it may be something like leaves built up under the wiper cowling, and water is filling that area up, just clean out the leaves. Leaky windshield can be fixed with a little caulk. And if it's door seal, well, install a brand new one.

Of course, if the floor pan is rusted through, and water is splashing up through, that ain't as easy to fix, but a quick patch job isn't that difficult.

Time for some detective wet-work!

Not a 1500 issue, but on my 2013 2500HD, one of the seals on the roof clearance lights was leaking rainwater in. It would just drop through the headliner in the same spot on the passenger floor. If you have an OnStar antenna, I'd check that- and your third brake light gasket. The drip is not necessarily where its leaking in from.