Windows and Windshield Foggy
#11
12-14-2017, 05:04 AM
The most common cause of windows fogging on any s-series vehicle is a leaking heater core. It causes the humidity level in the HVAC system to skyrocket and now that the weather is cooler it is condensing on the cold glass. It doesn't necessarily need to be a big leak. So not seeing fluid on the floor doesn't rule it out.
First check that the heater hoses under the hood are tight and not leaking at the heater connections. If they are loose or cracked the coolant can leak inside and cause your problem. If not you need to replace the heater core.
First check that the heater hoses under the hood are tight and not leaking at the heater connections. If they are loose or cracked the coolant can leak inside and cause your problem. If not you need to replace the heater core.
Last edited by oldeerslayer; 12-14-2017 at 05:08 AM.
#12
12-14-2017, 09:19 AM
Water could be leaking in through a faulty seal on a window or door. Next wash check the carpet for wet spots, especially in the back since that's the foggiest.
#15
12-14-2017, 08:19 PM
You said that all outlets are working properly, so no hoses detached in the dashboard. At the MAX blower setting the vents should deliver quite a stream of air and it should change to the respective vents when changing the setting. Make sure that the ones on the sides of the dash get an o.k. flow as well. It should be felt easily when on a medium fan setting.
Use MAX heat not an intermediate or auto setting. Check if it gets warm within a couple minutes the engine is running. It should warm up rather quick, then it will take time to get up to temperature.
The windows being the coolest part in the car when you start it in winter, all moisture that is brought into the truck by your clothing, breathing will settle on the windows first.
Do you smoke in the truck? It will mess up your windows quicker than if not smoking.
Give them a really good cleaning. Use a window cleaner spray and once cleaned use a lint free and clean towel or microfibre cloth and wipe them a second time, this time dry. This will remove all residuals.
The tiny micro particles on a sheet of glass act as condensation cores for humidity. The difference can be quite important in winter time and may make the difference between all fogged up and only fogging up a little bit.
I usually take off my overcoat/jacket/parka and hang it on the hanger at the rear door. Use full heat after starting with a medium ventilation setting. Blowing too much air sometimes does not help if it is not warm enough.
Check the lateral outlets that air is directed to the lower part of the side windows. It will start to flow up (warm air) and defog the sides. The rear windows in the Blazers are notorious for staying fogged until it warms up really good, except if you have the rear middle console vents, they help the in the rear.
When really cold and you get frost I normally start the truck first, put the heat to MAX and to DEF with a low fan setting. Then start to dig the Blazer out of the snow or start removing the frost.
Use MAX heat not an intermediate or auto setting. Check if it gets warm within a couple minutes the engine is running. It should warm up rather quick, then it will take time to get up to temperature.
The windows being the coolest part in the car when you start it in winter, all moisture that is brought into the truck by your clothing, breathing will settle on the windows first.
Do you smoke in the truck? It will mess up your windows quicker than if not smoking.
Give them a really good cleaning. Use a window cleaner spray and once cleaned use a lint free and clean towel or microfibre cloth and wipe them a second time, this time dry. This will remove all residuals.
The tiny micro particles on a sheet of glass act as condensation cores for humidity. The difference can be quite important in winter time and may make the difference between all fogged up and only fogging up a little bit.
I usually take off my overcoat/jacket/parka and hang it on the hanger at the rear door. Use full heat after starting with a medium ventilation setting. Blowing too much air sometimes does not help if it is not warm enough.
Check the lateral outlets that air is directed to the lower part of the side windows. It will start to flow up (warm air) and defog the sides. The rear windows in the Blazers are notorious for staying fogged until it warms up really good, except if you have the rear middle console vents, they help the in the rear.
When really cold and you get frost I normally start the truck first, put the heat to MAX and to DEF with a low fan setting. Then start to dig the Blazer out of the snow or start removing the frost.
Small note: I did have the heat go out in October. It was the thermostat. I did do a flush of the heater core. I did have a loose hose. I fixed that.
#17
12-14-2017, 08:21 PM
The most common cause of windows fogging on any s-series vehicle is a leaking heater core. It causes the humidity level in the HVAC system to skyrocket and now that the weather is cooler it is condensing on the cold glass. It doesn't necessarily need to be a big leak. So not seeing fluid on the floor doesn't rule it out.
First check that the heater hoses under the hood are tight and not leaking at the heater connections. If they are loose or cracked the coolant can leak inside and cause your problem. If not you need to replace the heater core.
First check that the heater hoses under the hood are tight and not leaking at the heater connections. If they are loose or cracked the coolant can leak inside and cause your problem. If not you need to replace the heater core.
#18
12-15-2017, 07:08 PM
I just found an idea. You may gather a bit of the fog that gathers on a windows with finger and taste it. The coolant is based on ethylene glycol, so would have a very specific taste. In contrary to a water vapors from recirculated air.
Good luck!
I'm crossing my fingers You don't have to replace a heater core. For me it's a most hateful car repair ever (I haven't done it on a Blazer though).
Cheers,
Mike
Good luck!
I'm crossing my fingers You don't have to replace a heater core. For me it's a most hateful car repair ever (I haven't done it on a Blazer though).
Cheers,
Mike
#20
12-15-2017, 10:57 PM
I just found an idea. You may gather a bit of the fog that gathers on a windows with finger and taste it. The coolant is based on ethylene glycol, so would have a very specific taste. In contrary to a water vapors from recirculated air.
Good luck!
I'm crossing my fingers You don't have to replace a heater core. For me it's a most hateful car repair ever (I haven't done it on a Blazer though).
Cheers,
Mike
Good luck!
I'm crossing my fingers You don't have to replace a heater core. For me it's a most hateful car repair ever (I haven't done it on a Blazer though).
Cheers,
Mike
If you try this, do not ingest any of it and minimize contact of it with your mouth. Ethylene glycerol is toxic but tastes somewhat sweet. This is why they warn you not to drain coolant onto your driveway since dogs and cats will lap it up.
Last edited by christine_208; 12-15-2017 at 11:59 PM.