2005 F150 Super Crew Cab

Vehicle has been sitting for about 3 days. Weather ranges between 20-50 degrees F. Went out this morning and there was excessive condensation on the inside of the windshield. When wiped with a paper napkin, it dropped off in rain-size pellets.

I have window visors; if I left a them down 1-2 inches, will this help?

 

if you have that much water vapor you likely have a problem - if there isn't an antifreeze odor inside (heater malfunction) then check and double check your carpet to make sure there isn't a leak someplace that isn't obvious

could also get the dry bags (various trade names) at lowe's or HD - people use them when storing a refrigerator or anyplace that stays damp, have a chemical inside to absorb moisture

 

If water condensates inside like that then there is water inside the vehicle. Pull up the plastic right inside the door and see if there is water in the wiring channels, if so, the 3rd brake light is probably leaking.

 

Water is in the vehicle, something isn't sealed.

I sometimes have this issue with my 02 Taurus, if I don't close my drivers door hard enough, it doesn't seal.

 

Add A/C drain to the possible list of sources. There's a TSB for this issue, as there is for the 3rd brake light issue. The A/C drain requires adding a rubber elbow to aid in draining the water away from the firewall. Which will prevent water from coming in around the poorly designed drain. My former 07 had this issue. What a hassle it was to install.