When running heat or defrost, the drivers side of the windshield will fog up....no leaking coolant or antifreeze smell.

sounds like you have a coolant leak from the heater core or a hose under the hood leaking you need help from a mechanic

Is the carpet wet on the passenger side? Sound like you got a heater core leaking.Have fun replacing it.

Check coolant level, if it's losing coolant, you may have a heater core leak. Does it smell like antifreeze in vehicle when defroster on? If by chance your ducting drain is plugged, it may just be water or condensation build up inside where core is. Antifreeze leak will also put a sticky film on inside of windshield, so if you wipe it with finger and it feels sticky, it may be a core leak. Be sure to double check heater hose connections in to firewall/heater core, just to be sure your leak isn't a bad hose connection before going to far if core appears to be leaking. A pressure test on system may give you a better idea what's going on. If all checks out and no leak apparent, be sure your AC compressor is engaging when in defrost mode, as that is what helps remove the moisture in the air during defrost. If compressor is not engaging, it will take much longer to remove moisture in the cabin.

Step 1: check to see if there is any leakage of coolant under the car, if so it could be a leaking hose or water pump seal.
If not
Step 2: check to see if there's coolant leaking on the passenger side fire wall (inside the car) and to see if there is any fogging on the windshield when the defroster is running, or if there's smearing on the windshield, this would indicate the heater core is leaking and has gone bad.

when u get that smell, is more likely to b heater core.

Do the windows (windshield) fog up for about 2 seconds if you switch the defroster on too? Sounds like you have a leak in the heater core. It's a small radiator located in the heater box inside the cabin of the vehicle. The blower fan blows through it to heat the cabin. If it's leaking or has a hole in it, what you are smelling is antifreeze. You can try a good radiator sealant and if that doesn't work. You'll have to change the heater core. Explorers aren't fun.

Sounds like a possible heater core failure(hole in it) the smell indicates to me the coolant(anti-freeze) is leaking into the passenger compartment.
Check the carpet in front of the front passenger seat for moisture, this would confirm heater core leak.
Good luck !

your heater core has probably sprung a leak.does the fog smell kinda sweet?....check the floor in the front where the floor mats are for moisture or even puddles of antifreeze.(the replacement of a heater core can be very expensive as the entire dash usually needs to be removed to access the heater core)also look under the engine near the firewall for antifreeze drips.

the small radiator just inside the cab, where the hoses go to the heater is leaking. You may try using stop leak (many don't recommend this) or take off the heater radiator. it will probably get worse when you turn on the heater and fog up the windshield if not fixed. hope this helps.

if you smell antifreeze ,and belive me youll know its antifreeze ,inside the car or the windshield will fog up when defrost is on ,you have bad heater core