I have the 1999 accord 2door, the heat works well, blows out of the front vents but will not change to defrost. I can here the hmm of the motor, and it sometimes works on the defrost on the pass side. I am a full-time student so money is an issue, is this something I can fix myself?

 

I don't know anything about the duct system, so the 1st thing I woulda' done is turn on the air conditioning with it full hot & on defrost.
On 2002, the book says that's the best way to get dry air.

In fact, it auto defaults to turnin' on the a/c when you select defrost.

Then if that didn't work, I woulda' turned the 'recycle' on........you know that button that uses inside air instead of outside air.
You could also try closing the two side vents [one by each front window on the dash]. My book says that gives you more air to the windshield.

Then, if that didn't work, I'd look into transferring to a college down south.

 

Thanks for the input, but the issue is the duct system my changing when buttons are pressed. The care puts out hot air fine, and will change to internal/external air when that is selected, but does not change from vent, floor, defrost ect. It is stuck on front vent setting. I read some about the relay switch in the fuse box, any ideas?

 

I would test/check the mode control motor and the linkage.

 

My problem is that the Windshield Defrost on 2004 Accord LX will not turn off No matter how many times I hit the button the light will not go off.I always have the AC on but the bottom of the windshield is fogged as well as part of the side view windows