Cooling System?

I have a 97.5 GS. 140000 miles. Original water pump and radiator. Recently the temp had been acting a little funny. At times temp go's above the 1/2 mark and sometimes it stays below the 1/2 mark. Fans seem to work OK. I replaced TS and still have same thing. Dexcool is about 30,000 miles old. Level is good and no leaks.. Even when I turn on A/C temp is hot. Fans seems to work OK. Car runs hot....Any idea's.....Could it be a clogged radiator, or a weak WP?....P.S....I do notice that both the fans seem to have 2 speeds. When the car is hot they both work at full speed. When it gets near the cooler side they seem to work at half speed. The secondary fan only comes on when the A/C is on.

I would start with the thermostat. It may be sticking especially if it is the original. Even if fairly new it could still be sticking. If you still have the problem then try flushing the radiator as it may be getting plugged. You can easily check this if you can touch the radiator. If one side is cold and the other hot then it is bolcked. Sometimes just washing out the fins and cleaning the debris between the ac condensor and the radiator can make a big difference.