i live in Alberta, so when i need defrost on my windshield i don't need it to remove moisture, i need HEAT to melt the ice and snow on the outside of the screen.
with my 2010 fit when i turn it onto defrost the AC fan kicks in. now this is a problem for me because when it's -20c (or even colder) the AC fan helps cool the engine too much by drawing cold air through the radiator, so my heat isn't hot enough.
so i have to turn the heater to face/feet setting, then the fan stops and the engine warms up again. but then the screen freezes.. so I'm constantly swapping back and to.


i searched and found the trick to disable the AC fan (hold button for 7 seconds etc) but it didn't work.

so how can i disable this? i don't want the fan cooling through the radiator when it's already freezing outside. i need all the heat i can get or the car freezes up..

my dash has the 3 heater controls in a vertical stack to left of the radio. so looks different to the pictures I've seen showing how to pull the plug to disable this..

any tips?
thank you

 

Here's what I do, but note it will not work on full defrost.
1) Turn the dial to floor/defrost. This will direct 50% of your air to the floor, and 50% to the windshield. In this setting, the A/C will also run.
2) Turn back towards floor until you hear a quiet click in the dial. Do NOT turn all the way to full floor. Air will still distribute 50/50, but the A/C will not run.
3) Move the slider to FRESH. Do not use recirculate, except to warm the inside of the car. On recirculate, moisture builds up inside, and while using recirculate in the summer on A/C helps the A/C to run more efficiently, in the winter fresh air is better. On recirculate I find that eventually in the winter the car begins to fog up.

I usually don't worry about whether the A/C is running or not. Drying the air inside the car does actually help to keep the windows from fogging up, and I don't find any appreciable change in mileage.

Note: Again, this does not work if you want full defrost. There is a wire connected to the back of the selector dial that you can disconnect to prevent the A/C from running, but I have no idea where that wire is.

 

I hate to say it, but having the AC on will keep the car from fogging up too much while it circulates the heat to the windshield. Without it, you get lots of fog on the glass really quick (at least in my experience).

Remote start and a 51R (Civic) battery are about the best upgrades I've made to this car. Always starts and running the defrost for 15 minutes while I shower in the morning on the really cold days helps immensely. Also, pull your wipers away from the car when you park. It keeps them from sticking to the windshield over night.

 

Thanks for the replies, but you are both missing the point.

Where I live there is no moisture. In the winter here humidity is basically zero.
Running the ac also runs the fan, running the fan cools the engine. So when it is minus 20, or 30 or even 40 Celsius the car gets cold. Especially on highway driving when just cruising at 80-100kmh. Which is mostly what I do.

My other car doesn't have ac and never fogs up.
I just want the ac off for when on defrost.

And I disagree about remote starters being good. Having a cold engine idle for long periods is terrible for a car. It has been proven the best way to warm a cold engine is to drive it gently after letting it idle for maybe 30 seconds just to circulate the oil.
Extended idling is very bad for your engine, because it doesn't get enough heat so it wears excessively.

 

I think I caught the point. I'm familiar with prairie winters, by the way, since I live in Saskatchewan. The humidity isn't coming from outside the car, it's from you breathing inside. Yes, it's a dry cold (so goes the old joke). I also do understand your point about the fan running and cooling the engine.

In my case, I don't have an issue with overcooling on the highway, but that's because I live in a major city, so by the time I reach the highway, my engine is fully warmed up, and the cooling fan will run periodically to help keep the engine from overheating anyway. The times I've visited my inlaws (who do live in a small town), I haven't really noticed an issue, either.

As much as I don't have an issue with it, you do. So, I found some light reading material for you.

This: https://www.fitfreak.net/forums/fit-...-selected.html

This: https://www.fitfreak.net/forums/2nd-...e-defrost.html

And this: https://www.fitfreak.net/forums/2nd-...c-defrost.html

Oh, and this: https://www.fitfreak.net/forums/gene...i-disable.html

I haven't read these threads to see if the instructions are in them, but I suspect they are. Happy reading!

 

Good job pointing out those threads. I used one of those guides to disable the A/C while in defrost and mix modes. It's super simple. You just remove a panel below the controls and with the flexibility of a five year old you can look up into the controls. Use a long flat-head screwdriver to slip the A/C connector from the back of the mode selector.

 

I do this on every car I have ever owned (well I still have to find the way to do this on my Sienna 12). On Fit I did this in hard way (taking apart some panels) and then I realized I could do it while removing lower small panel only. I'm glad that there are people on the planet that use their brain wider than any manufacturer allow them. I'm working now on condenser/radiator fans to provide 2nd (lower) speed for them to eliminate that horrible noise when it is really not needed. Most cars have 2 speeds on those fans. Temporary and for winter I have disconnected one of the fans (the one that is making more noise, in my case radiator fan which is on the right side), so less cooling still cold engine(if A/C button is pressed), less noise and less juice from battery (one fan is drawing 8 Amp) Any idea would be appreciated.