|
The reasoning behind running the A/C is sound. At a given temperature air is capable of holding a certain mass of water. Drop below that temperature and the water condenses out. (This is why it rains or snows.) Precooling the air before reheating dries the air by allowing the water to condense out on the A/C evaporator core and drain from there to outside the car. That makes the defrosting more effective.
Disabling it at the relay that switches the A/C clutch will be easiest. It is possible to connect through the brake light switch (or an additional switch) and still have the A/C, essentially for free. There does need to be some hysteresis in the switch or the cycling can be too rapid, such as when a brief brake application is used.
A warning though: the brake switch may be an input into a body control module and not switching the brake lights directly which will affect how you can wire it.
If there is an issue with the on board computers expecting A/C on and not getting it, there should be an evaporator temperature sensor that cuts out the A/C to prevent the evaporator freezing. Emulating that signal as 'cold' would prevent the compressor being switched on.
|