1999 Honda Accord Overheating with A/C on when sitting idle

I noticed that my car began to overheat when I was sitting in a parking lot with the A/C blowing. I popped the hood to check for coolant leaks and found none. My coolant reservoir still had coolant at the appropriate level and my upper radiator hose was firm, so I knew that there should not have been a blockage that would cause the car to overheat. I turned the A/C off and began to drive around to see if the car would cool down. After about five minutes of driving, the car resumed to its normal operating temperature. After looking at the car when I returned home, I noticed that the driver side coolant fan was not kicking on and that when the car sat idle with the A/C blowing, it was wanting to start overheating again. I disconnected the fan and jumped it straight to the battery and it began to work.

I replaced the coolant temp/fan switch sensor ( pt# T254) located on the water neck and the fan still does not come on to prevent the car from overheating.

Does any one know why the fan is not kicking on when the cars temperature begins to rise?

Also, is the driver side fan the coolant or A/C fan?