Why does it occur? Think about it...if you park in a garage & drive into cold weather, the air inside the cabin will be warmer than outside the cabin causing condensation on the inside of the windows. This can cause loss of visibility, especially at night which can become dangerous.
Solution 1: Clearing the windows when they fog up.
While this may seem like elementary information for some, many do not realize that your Air Conditioning can be used with the car on max-heat & still blow hot air! The a/c does NOT necessarily mean "cold air". The a/c compressor removes moisture from incoming air. If you put your car on defroster mode & throw the A/C on, you will notice the fog clear up very quickly. On many new cars, the a/c automatically comes on when you select the defroster mode from your HVAC controls, but our cars don't have this luxury
. Solution 2: Preventive Maintenance.
When your windows fog up, do you see swirlie marks appear from the last time you wiped your window off? Is the fog becoming increasinging more diffiicult for your a/c to remove? If so, the inside of your windows need a GOOD cleaning. Simply wiping them down once with windex or auto-glass cleaner is NOT ENOUGH. Even after doing it 3-4 times in a row, there will still be some oily residue leftover. This residue is caused by vapors in the interior plastics releasing & clinging to the window over time. Also if you smoke in your car, the tar & other crap from the cigarrette smoke will also cling to the windows creating a haze.
So how do you remove this? Household VINEGAR! May seem ridiculous, but it works great!
-Get 3-4 paper towerls, quadruple one up & press it against the vinegar bottle.
-Flip the bottle quickly upside down & back up to get some vinegar on the towel. You could use a spray bottle to apply it directly to the windshield, but droplets will also get on your interior panels & create a lingering odor. Applying directly to the towel will prevent this.
-Wipe down the window w/the towel a couple times.
-Use a clean towel to remove any wet vinegar remaining on the window
-Now spray regular window cleaner on the window & wipe it off to remove any odor
-Wipe the window again with a clean towel
If there is still a couple of swirlie hazy areas remaining...wipe that area down more thouroughly with vinegar.
OVer time your windows will regain the nasty hazy gunk, so every now and then (probably once a year will do) clean them with vinegar!
