96Grand Am: when rains- puddle at feet on driver’s side. Water comes up from carpet; Window has been replaced; window motor on driver’s side has been replaced; gone on for 3 years now; mechanic doesn’t know
Same problem with a 2000 Blazer. Ran water into the windshield cowling while looking under the dash with a flashlight, water was leaking through the seam between the inner fender and the firewall. The water ran down the firewall under the carpet and came back up in through the carpet by the seat. The truck had been in a minor accident on that side before I bought it. Sealed the seam and no more leaks since 2003.
There are a number of possibilities. First, do you have a sunroof? If so a blocked drain is a very good possibility. Also consider a blocked drain in the grilled area in front of the windscreen. The windshield may be leaking. You may also have a rust hole under the carpet. Finally the door may have seals or blocked drains.