Driver's floor wet after rain. Sealed everything. ???

My 96s driver side floor board is wet whenever it rains.
I can see a small trail of moisture coming down the firewall inside, just above and left of the fuse box running down the left corner of the firewall from way up high.
I've replaced my windshield and sealed the firewall to cowl pinch seam in the engine bay all the way across. No firewall gasket are worn and my booster firewall seal looks good with no moisture around it.
I've looked under the cowl/wipers plate and can't see any standing water or anything obvious.
Don't know how the hood seal, between hood and cowl, is attached but could it be getting in from the hood seal?

I"m at a loss. Thoughts on the source of the leak?

Common leak areas and causes are:

Windshield seal
bad door seals
poor door fit to door seal
am/fm antenna opening above fuse box
firewall/cowl seams
rust holes in wheel well and/or floor
failed firewall seal around a/c line, blower fan, condenser lines

Found it!! It's where the front driver botom corner of the cowl meets the firewall. There's a tiny hole.
If you look underneath the driver side of the dash, all the way up in the far left upper corner where firewall meets the cowl and side interior it's right there, so I assume there's a hole in the forward left bottom corner of the cowl interior as well.
What would be the proper method of repair to eliminate further rust and seal it properly???
Where are the actual drain holes for the cowl???

I know what the problem is now, just dunno how to fix it.

Remove rust and paint any bare metal as you would with any other body work. The cowl outlet drain holes are in the unibody as shown in the pic. The inlet holes are in the interior corners of the cowl cavity.

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I just noticed the same problem. Im thinking of cutting above the cowl and sealing it soon. My passenger floor is soaked after it rained

don't cut it up! hit the firewall/cowl seal with seam sealant before. also check the heater box to firewall seal. they fail and leak too.

Bronze.

Do you have a pic of the Firewall/cowl seam is located exactly?

Thanks

The seam is often not sealed and water will wick into the seam and then drip into the interior. The seam runs all the across the engine bay. Make sure the end corners are water tight also.

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Thank you!

i had a leak on my drivers side in my 01, ended up being my own stupidity. way back i pulled the gasket for the hood release cable to run a wire for the amp and didnt seal it again, water ran down the release cale and in to the cab. i rerouted the amp power and reinstalled the gasket, no more leak.

i had a passenger side leak on a 98 and finally got around to "fixing" it. turns out mine was a bad seal between the HVAC box and firewall. water would dribble down the firewall and on to the blower motor housing and in the cab, not the best design if you ask me. i certainly wasnt wanting to pull the whole dash out and drain/recharge the a/c just for that, so i used my exterior siding skills and bent up a small piece of flashing to divert the water.



works great, never get a drop inside anymore. i pulled the carpet out, dried it out and took care of the surface rust in the pan(thankfully it didnt go too far).

water leaks in the cab are tough to track down, lots of possible reasons exist and a number of ways to fix them.