The Disco has set since Saturday afternoon. I came home this evening an found a wet spot on the passenger floor mat. It has rained today, but no one has been in the truck and all the window's and sunroof's were closed.

I pulled the black panel from under the glove box and found a few drops of water (there is no coolant smell) on the foam, but it certainly wasn't soaked. I also couldn't locate any source for the water (or fee any more dampness).

So, where is this coming from? It is most certainly not coolant

 

Check above the windshield at corner near door.

 

What would I be looking for? Are we assuming that the windshield seal has a gap?

 

The windshield seal can leak and the roof liner be wet at that corner. Of course with sunroofs, there is always a chance for a leak, their plumbing cracks off behind the roof liner, and sometimes their drain is blocked. One member reported his leaked only whe truck was parked on a hill.

 

If I leave my DII out in the rain facing downhill or level I get rained on when I drive it. I believe it is the sunroof. If I park it uphill the water runs out in the back near the back door down the headliner. could be either windshield or sunroof

 

sound like sunroof drain problem

 

I know it's the wrong time of year to be running the A/C, but when was the last time you cleaned your A/C drains out? If they are clogged the tubes will fill up and spill over in to the passenger floorboard. My 2000 DII used to leak in the passenger side floorboard untill I ran clothes hanger up the little rubber nipples(2) on either side of the Transmission. Mine only leaked when I ran the A/C though, so unless you ran the A/C recently(even with defrost mode) I'd put my money on the sunroof. Notorious for leaks that run on the top of the headliner and actually pour out in different places in the truck, depending which way the truck is parked. Never hurt to check those A/C drains though!

 

^This is what I originally thought but he said it was just sitting.

 

Yea, probably the ole sunroof problem then. Unless perhaps it leaked durring the last drive and was just overlooked untill now. Unlikely, but possible. Things stay wet a long time in a closed up truck with no ventilation and all. Money is on the sunroof since it's just rained and all. Hope this helps. Please make sure that when you do find the cause and repair it to let us know what it was and what you did. Too often we never hear back. Until then, we'll be here!

 

Probably not your issue but for those others with mystery wet spots, I recently had a gasket fail on one of the roof rail bolts, drivers side above the rear seat. this lead to water on the headlining just above the rear door and nowhere else.

I've not heard of anyone else having this issue so if you are leaking in that area check your roof rails gaskets. this was the one between the rail and the roof.

Otherwise its either your sunroof or AC drain nipples need massaging.