Check first if your Main fan high speed setting is still working. Usually it will switch on just past the middle of your temp. gauge.

Kung okey pa, baka masayang lang pera mo.

Etong car ko kasi basta nka start with aircon on ay gana narin yung auxillary fan pati na yung low speed setting ng main fan. Pero pag hindi on ang aircon patay sila dalawa until the temp ay medyo lampas na ng half of the temp gauge, in which case mag-switch on na yung high speed ng main fan, yung auxillarry fan on na rin. Sandali lang lamig na temp at switch off na naman sila.

But if what is happenning with your car ay wala naman dati, maaring me problema na cooling system mo like clogged radiator, weak pump output, coolant leaks, defective thermostat(di na bumubuka ng husto), coolant hose collapsing at high output situation or if rear wheel drive, defective fan clutch.

Pero may mga sasakyan talaga that sometimes ay kulang sa disenyo from the start (or nag-iba na ng setting dahil sa gamit) lalo na sa extreme situation kaya yung iba they opt to add extra fan, replaced the radiator with a bigger one, replaced the clutch fan with heavier duty type (pang turbo engine, pang truck, yung may mas maraming cooling fins, kala mo tuloy jetplane na umaandar, sobra ingay), tanggal ng thermostatic valve, which the owners will swear na nag improve yung sasakyan nila.

Maraming pros and cons pero depende na rin yan sa car mo at sa current condition ng car mo, sometime what may work for one car may not work for you or vice-versa. But take it easy, spend your money well.