There is no big deal whether the mesh act as a barrier high enough to deplete air flow.
The fan is able to draw constant air flow through the radiator.
It will not overheat.
Have you tried getting stuck in a massive traffic jam in mid afternoon sun ?
Nothing happens. Your fan keeps blowing, that's all. Having a OBD-gauge helps you determine your engine coolant temperature, and from what I had experienced, the temperature in mid hot day sun and mid night , yields the same temperature while idling. The system is regulated to around 90 degrees and the fan will switch on if the temperature rises.
And yes, that is the A/C radiator. The engine coolant radiator is usually mounted sandwich behind the AC radiator. Both are called radiators.
About speed , I don't get your point when you say you dont get cooling efficiency, especially high speed driving ?
A car radiator fan does not work dependent on the speed of the car. It is dependent only on the temperature.
Whether the car is speeding at 90km/h or 190km/h, as long as the temperature is below its threshold, the fan wont switch on.
But should the temperature rose above it's threshold even when it is going at 190km/h, the fan will still insist to blow, despite the air flow through the radiator would had probably surpassed the flow rate of the fan's capability.
A tip on overheat and AC.
If you wish to lower your coolant temperature quickly, you should switch on your AC fan to highest speed and disable the AC mode, turn the knob to extreme clockwise to the RED side maximum heat.
The AC make use of both freezing air from the AC pump, mixed with the hot radiator coolant that passes through the AC system to achieve the required temperature you desired.
By switching off the AC mode, there is no cold air going through the system, thus the system is only blowing hot air that is circulated through the system. The maximum fan speed will quickly cool down the coolant by several degree within a minute.
You will be able to witness this if you have a ODBgauge installed.
I tried this usually whenever I got back to my home, I would switch off AC mode, heater to max, fan to max, I would watch the temperature reduce from 90-92 down to 85-87.
I did this not to cool the engine actually. Just coincidentally I realize it. I use heater to dry up the AC system air duct to prevent mouldy build-up due to moisture remaining in the air con duct after I switch off the car engine.
Edited by carloverguy2017, 07 August 2017 - 12:50 AM.