I recently noticed that my driver's floor mat was wet and stayed wet. It didn't occur to me as anything out of the ordinary as it can get wet from my feet but typically dries quickly... At first, I was worried it could be something like the heater core but it's just water (based on smell). Quick research suggests it's probably a clogged (sunroof) drain. I seem to have gotten conflicting information about where it drains though. Some have indicated it drains in (2) directions - one to the passenger side front and one to the driver side, but down the C-pillar. In my case, the front passenger floor is dry.

I haven't torn anything apart yet. Before I do, can anyone point me in the right direction ? The carpet is wet currently (it rained like mad yesterday and the day before) but the floor 'pan/firewall' area is visually dry. It's been 12-24 hours since it rained, so I'm not surprised.

Do I do the "hose test" - have someone run water over the roof and see where it comes in ?

'99 Accord EX

 

There are drain tubes on all four corners of the moon roof. The front drains run down the pillar that is between the windshield and door. I think that is the A-Pillar. The rear drains run down both C-Pillars (next to the rear window).

You should be able to open the moon roof and see the drains in the corners.

 

Front drains are in the A-pillars next to the windshield. But somehow they connect or poke through somewhere so they drain into the front wheel wells in the general area of the door hinges. I guess it's possible for that hose to become unhooked from where it belongs & drain into the interior footwell??

 

It looks like it (the front drain hose) runs down the "A"pillar and into the front kick panel, before it pops out (at the drain valve) thru the foot box area (firewall). So if the floor is wet in the area where your feet (heels of the shoe) sit, then the hose might be off at the valve. If it's more toward the seat, then look at the ceiling and see if the headliner is wet/damp, as that'll tell you which end has the problem.
On my 65 VW Notchback with factory sunroof, I'd run an old piece of clutch cable thru to make sure the drains are open, as it's a similar design that Honda uses (4 drain hoses in the corners of the drain tray).

 

If you poke something through the drain hoses, I'd suggest plastic string like used in a weed trimmer. Less likely to poke a hole through the side of the rubber hose.

 

Thanks for the comments everyone. Once I contorted myself upside down under the dash, it was clear as day what was wrong ! The drain tube had simply popped out of the elbow-grommet that goes through the firewall. It took me more time to get myself in and out of under the dash than it did to 'fix' it !!

 

Good Job. Congrats on getting it fixed. We like hearing the result of a problem. Glad it was an easy fix (other than contorting yourself).