This one has me stumped

[BigRondo]

The other morning I left the house at about 6:00 AM and the inside of my windshield kept fogging up. The overnight temp was in the mid to high 60's and the temp when I left was in the high 60's to low 70's. I was using the AC the day before but shut it off when I parked the Ex: Fan on 1, Temp on cold, Vent Selection on off.

I have the blend door issue and the fresh/recirc door issue, so I keep the temp set on cold for fear I won't get it off hot. One time, and only one time, the vent selection didn't work and it was briefly stuck on defrost. I don't know if these issues are related.

I had to keep using the defroster (set on cold) to clear my windshield. I noticed the fogging of the windshield stopped when I rolled down my 2 front windows when It started getting warmer out.

In the past, on my older cars, when the inside of the windshield fogged for no apparent reason it was usually a bad heater core. Thing is I don't smell anti-freeze inside or outside the Ex.

Any help will be appreciated. Thanks - Rondo

 

[matt0248]

Foggind depends on temperature of the glass and humidity. On my X if it is really hhumid the window will fog up if the air conditioning is on. It fogs up on the outside though. Wiping with the wipers cleans it off. It is because the moisture in the air outisde is condensing on the cold glass.

 

[BigRondo]

Foggind depends on temperature of the glass and humidity. On my X if it is really hhumid the window will fog up if the air conditioning is on. It fogs up on the outside though. Wiping with the wipers cleans it off. It is because the moisture in the air outisde is condensing on the cold glass.

Matt, thanks for the reply. I know about the fogging on the outside of the windshield. This was happening on the inside of the windshield.

 

[ncranchero]

May be the A/C drain is stopped up and not letting the condensation drain out........

 

[BigRondo]

May be the A/C drain is stopped up and not letting the condensation drain out........

Any tips in locating this drain? Thanks.

 

[BigRondo]

btt

 

[ncranchero]

Oh, sorry. Generally the drain is on the right side under the HVAC box. Question first though. When running the AC on a humid day does your Ex leave a puddle everywhere you stop? If so then your drain is okay.

BTW, check under your floor mats/carpet for signs of moisture from an undetected leak. If the air in the vehicle or even in the heater case is humid and warm the blower will send it right to your windows. Or it always seems that way.

 

[BigRondo]

Steve, I do get the puddle when using the A/C. But I'm thinking that it doesn't puddle like it should, comparing it to other vehicles. I will check for a clogged drain hole. I did go searching for a leak because I know any moisture in the vehicle will cause condensation on the inside of the windows. I had a 75 Mazda that I had to use the ice scraper on the inside windows in the winter. That was fun. I'll post back with the results. Thanks for your help. - Rondo

 

[BigRondo]

Update

No fogging windshield since my last post. Go figure.

 

[workman482]

After thought

Interesting, just a after thought. My 04 xls had the fogging problem. Ended up being an obstructed vacuum line causing the vent door not to swing from defrost to vent.

But, it's best to following the age old adage: "if in isn't broke, don't fix it."

 

[BigRondo]

Interesting, just a after thought. My 04 xls had the fogging problem. Ended up being an obstructed vacuum line causing the vent door not to swing from defrost to vent.

But, it's best to following the age old adage: "if in isn't broke, don't fix it."

Workman, when vent is selected, the air blows out the vent like it should. Just for sh#$ts and giggles what vacuum line was obstructed? Thanks

 

[workman482]

The lines pinched were a orange and black line running across the bottom of the fan. One is the main vacuum likne coming from the engine, the other is the vacuum control line running to heater hose vacuum control. It turns on and of the coolant going to the heater core, in theory.

I had pinched them by accident when I removed my blower motor and didn't make sure they were out of the way when I bolted it back in.

 

[BigRondo]

The lines pinched were a orange and black line running across the bottom of the fan. One is the main vacuum likne coming from the engine, the other is the vacuum control line running to heater hose vacuum control. It turns on and of the coolant going to the heater core, in theory.

I had pinched them by accident when I removed my blower motor and didn't make sure they were out of the way when I bolted it back in.

Thanks, I'll take a look at the vacuum lines.