The triple digit temperature here in south florida can reak havoc on the cooling system. I bought a 10 inch cooling fan for $25 of ebay and a lighting switch fit (lighted on/off switch, 30 amp fuse and holder, and a 40 amp relay) for $19.99 at pepboys.
I wired it where I can turn it on or off ONLY IF THE KEY IS IN THE "ON" POSITION. Also when you engage the "TOW" switch, it comes on. The control switch has a green light (Fan is running), and a red light, (fan is off).
Remove the key and NO POWER TO THE FAN.
When the car is idling and I turn on the a/c, the water temp needle drops a tick below the the center line mark. The a/c runs noticeably a tad bit cooler. If you dont have the tow package but still tow, I recommend the 15" cooling fan.