I have a 1992 Lexus es 300 and just got my radiator flushed the other day, its been pretty cold here and I've noticed that my defroster isn't defrosting the side windows or the top corners of the windshield very well. Any suggestions on what to do or what the problem might be. I make sure to turn the heat on high with the fresh air button on and the a/c button on as well. Thanks

 

a/c button doesn't matter with heat, and personally, I'd use the recycle air button - the blower blows harder with it in that position...

 

I have a question:
Was does the green A/C light always come on when I press the "Front" defrost button? Is this normal?

 

The blower doesn't blow harder in the recycle position, it just sounds that way. The noise is louder because the air intake is inside the cabin instead of outside, where it is on "fresh". It's like having a vaccuum cleaner nozzle inside the car instead of the outside.

I wouldn't recommend the "recycle" setting in cold weather as this leads to fogging up your windows. "Fresh" will keep them dry.

The A/C light comes on during defrost because the newer cars use the A/C to dry out the air to facilitate defrosting. The A/C and the heat are on simultaneously, but the heater wins out. This is normal.

As to the defroster problem, the issue is one or more of the following:

Blockage in the vents.
Vent door (directing the air) stuck or malfunctioning.
Vent fan malfunctioning.
Defrost control switch malfunctioning.
Heater core valve stuck or malfunctioning.
Heater core plugged.

I think that covers all the usual suspects. You can check out the first four by placing your hand over the defroster vents and seeing if there is a significant air flow. The last two can be checked by heat output. Do any of the vents or settings put out significant heat?

The defrost setting should accomplish all of these. If not, you'll have to start tracing down each potential problem.

 

I just double checked, but in my car, I can feel (hand over the vent) a difference...

Checked my brothers Eclipse and fiance's Maxima... both do the same thing...

 

I think the problem is one of the later two you mentioned? i'd like to fix this myself if its not that big of a deal, the air flow is fine in my opinion, but not 100% sure it seems to be blowing just fine and the car heats up in a timely fashion. Is it something to do with not getting the humidity out of the car or something like that. I read that somewhere on line. Thanks