When I turn on my defroster to clear the window, instead of clearing them I end up with more fog on them. There's no antifreeze smell or anything so my heater core isn't leaking.. I know it pulls air in from outside....Does the heater box/air intake box have drains in it anywhere that could be plugged...holding water in and steaming it onto my windows? I looked in the FSM online but it doesn't give a real good breakdown of it.

If anyone has any ideas i'd appreciate it. It's a 90 4x4 thanks!~

 

If you have AC turn it on when you want quick defrost. You'll be amazed how quick it defogs. Domestic vehicles have the AC come on automatically on defrost - my 1990 Toyota does not.

Sorry to ask since you addressed this, but are you sure you are drawing in fresh air - have you checked the flap itself or are you just basing it on where you have the control lever?

Beyond that the only advice I can give you is turn the heat way up so that it helps to evaporate the mist.

Did the defroster used to work better?

 

Definitely use the A/C with heat on high; it will defrost in short order.

 

X3 Ac

 

Ac X4

 

I don't have AC... plenty of other vehicles that I have drive at work don't have AC either and they defrost fine...that's why I think water is trapped in the heater box.. does it have a drain???

 

You either have a moisture problem in your heater box, not drawing fresh air in or else you have a slight leak in your core.

To answer your fresh air question, open the passenger window. There is your fresh air.

The other two problems pretty much require pulling the dash apart and doing a visual inspection.

There should be a drain tube coming out somewhere behind and to the left of the passenger front tire you could try and fish a solid core 20 gauge wire up it to see if it's plugged.

 

Thanks! I'll try that... I know there's gotta be moisture in it somewhere because I'll have a little fog on the windows, and when I turn it on it's instantly so foggy that I can't see, but it will eventually clear up after running the thing on hot for like 10-15 mins, and it's been raining alot lately so I'll look to see if its plugged

thanks again

 

has it been raining where you live a buddy of mine had the same problem his was the windsheild had lost its seal and water was leaking in he never saw water dripping but it was. the way he found it was he was cleaning the dash and the bottom of the windsheild pushed up.

 

I checked the drain, it was plugged solid! We'll see if this helps dry it out.

I said my truck doesn't have AC...but really it does, just doesn't work...I'm gonna have to charge it up and see if it holds..

thanks for the help!

 

The way your A/C is wired is to come on anytime you turn the defroster on. So yes, it would be of great benefit to get it fixed.