Help Needed: Unlink A/C to Defroster

[CTScott]

Originally Posted by stran

I have a '07 hatchback.

PS How do I subscribe to a thread if I forget to do it when I post?

07 and 08 use the same ribbed knob switches and 09 has knurled knobs. I looked at the EPC, but can't figure out from the wording, which switch is the one which doesn't automatically turn on the AC when in defogger mode.

Go to User CP (control panel) and click on list subscriptions, then you can select the notification method for threads that you have posted in.

[IllusionX]

Originally Posted by jambo101

Tried that and the windows start fogging up again,seems some airflow is constantly needed on the window to keep it fog free' but just warm air will do the job once the car is at operating temperature,at that point the air is no longer needed but there is no way to turn it off and still have airflow over the window.

I don't know about yours, but both, the echo i've had and the yaris i have now constantly have a good amount of air coming out of the defrost area when it is set to foot only. If your car does fog up even when fully warm up without activating the front defrost, chances you are running with recirculated air all the time.

Originally Posted by stran

Except the connection to the heater is probably via a mechanical linkage. I know that the vent knob operates via a mechanical linkage. With the car off and there's no power, you can still switch between the vents. On luxury cars I've driven before, the soft buttons activate a little motor that open and closes the damper that only works when the car is on.

the connection to the heater is activated by a mechanial linkage that activates a switch. it COULD be the same switch as the AC switch when on defrost mode. My echo only had one switch there.. so...
i don't know if this helps.




By the way, even in Cali, your front window fogs up, especially during rainy days. when setting your vent to front defrost, the AC actually helps in defogging your windows.

[stran]

My first DIY post.

Total Time:

7 mins (if you know what you're doing)
20 mins (if first time opening the dash)
2 hours (if you're have two left hands or missing your opposable thumbs)

Tools:

Small flathead screwdriver to disconnect wire harness and push in the little clips that holds the plastic pieces together. (But not required. I could have done it with my keys or just my fingers.)

Follow instructions for changing the LED to access the back of the vent dial. Everything comes apart really easy. On the back of the circuit board (the one with the A/C button), there is a momentary switch (momentary means it requires continuous pressure to be closed) with a little metal arm. I know this description is vague, and I'm sorry I don't have pictures, but there's nothing else on the back and once you're there, it'll be obvious. Bend the metal arm a few times and it breaks right off. Presto! No more annoying A/C with defrost. Reassemble.

How it works: the back plastic piece has a ridge that engages when the vent knob is in the defroster mode. The ridge presses on the metal arm to trigger the momentary switch. No metal arm means the ridge can't trigger the A/C switch.

For the belt and suspender people to check you have the right switch (which is what I did), you can turn on the car and press the switch and see if the A/C turns on. It's easiest to tell when the car is fully warmed up since the difference in idle speed between A/C off and A/C on is very noticeable. I also had a scangauge to check fuel flow, but you can open the hood and check the condenser fan.

Tips:

• Leave the vent dial knob all the way to one side (like face vent) so when you reassemble, you don't have to worry about aligning the indicator.
• There's a little bit of grease on the knob to lubricate the gears. Having some paper towels is handy.

Man, this mod made my week. I've been pissed at my defroster for so long. Though, the knob has a few sticky points. I didn't pay enough attention before to know if I made it stickier or it has always been this way. I can't think of anything I did that would affect the smoothness of the knob.

[CTScott]

Originally Posted by stran

My first DIY post.

Total Time:

7 mins (if you know what you're doing)
20 mins (if first time opening the dash)
2 hours (if you're have two left hands or missing your opposable thumbs)

Tools:

Small flathead screwdriver to disconnect wire harness and push in the little clips that holds the plastic pieces together. (But not required. I could have done it with my keys or just my fingers.)

Follow instructions for changing the LED to access the back of the vent dial. Everything comes apart really easy. On the back of the circuit board (the one with the A/C button), there is a momentary switch (momentary means it requires continuous pressure to be closed) with a little metal arm. I know this description is vague, and I'm sorry I don't have pictures, but there's nothing else on the back and once you're there, it'll be obvious. Bend the metal arm a few times and it breaks right off. Presto! No more annoying A/C with defrost. Reassemble.

How it works: the back plastic piece has a ridge that engages when the vent knob is in the defroster mode. The ridge presses on the metal arm to trigger the momentary switch. No metal arm means the ridge can't trigger the A/C switch.

For the belt and suspender people to check you have the right switch (which is what I did), you can turn on the car and press the switch and see if the A/C turns on. It's easiest to tell when the car is fully warmed up since the difference in idle speed between A/C off and A/C on is very noticeable. I also had a scangauge to check fuel flow, but you can open the hood and check the condenser fan.

Tips:

• Leave the vent dial knob all the way to one side (like face vent) so when you reassemble, you don't have to worry about aligning the indicator.
• There's a little bit of grease on the knob to lubricate the gears. Having some paper towels is handy.

Man, this mod made my week. I've been pissed at my defroster for so long. Though, the knob has a few sticky points. I didn't pay enough attention before to know if I made it stickier or it has always been this way. I can't think of anything I did that would affect the smoothness of the knob.

Excellent!!!

[auxmike]

[stran]

sorry dude. i don't have a digi cam. it'll be obvious once you get there.