99 Taurus / 98 Windstar both act like the drivers door is open when weather is wet

Hey any / all -

I have a 98 Windstar GL w/ 3.8 and a 99 Taurus SE w/ 3.0. They both exhibit the same problem.

Whenever the weather is wet, they act like the driver's door is open even when totally shut. The dome lights remain on, the open door idiot light in the dash stays on, and in the van the repetitive 'bong, bong, bong' goes on for several minutes before it times out. I determined it is the drivers door in both cases by hitting the power locks with the doors shut and the engine running. In both vehicles, the driver's door unlocks as a safety feature to prevent folks from locking their keys in the ignition.

I have had the door panels off in both vehicles and didn't see anything obvious. Unfortunately, I do not have a garage and both cars remain outdoors.

Does anyone have any experience and perhaps a solution?

Thanks

Greg