Just guessing, but it could be a stuck open thermostat. Check your pipes from cold. Start her up, and check the temperature of the plastic pipe that runs across the front of the block (just above the oil filter housing) and check the top radiator hose. If they both warm up together, then you're thermostats stuck open. It should be closed when the engine is cold so that it can warm up quicker by not going through the radiator. As for your fan switch, it's two stage (low/high speed). Stage I comes on at 92-97deg, Stage II comes on at 99-105deg, Stage II drops down to Stage I at 91-98deg and S