Intend,
2004PT hit it on the head. If the fan doesn't come on when you turn on the A/C then the high speed part of the fan motor is burnt out. It happened to mine. Since it does cycle on and off, the low speed is working but not enough to cool the engine down with the A/C working. I'm up in Virginia right now but can help you replace the fan (fan about $100 on eBay or a lot more from the dealer) and you can save alot in labor charges. But, I won't be returning till the 5th of May. If you can't wait till then, let your mechanic change it for you.
To check the high speed fan, disconnect the fan clip (see picture) and add hot and ground wires to fan part of wire harness. Fan should come on. If not, it's burnt out.
