Seems that my air conditioner is cycling a bit much, while driving I feel the air going from very cold to moderately cold. About 75 degrees out today, I went to check the pressure at the low side (or what I knew to be the low side) at the front of the hood, with A/C labeling 6NM on cap, my fill tube with gauge doesn't fit. Am I missing something here?

 

the ports for the low side and high side are different sizes on most cars (to avoid the obvious problem trying to fill on the high side...). The low side is the line from the firewall back to the AC compressor - high side is from the AC compressor to the condenser

 

So where is the low side fill port on my car? I thought it was the one near the radiator, but am I wrong?

 

That's the high side. The low side is near the coolant reservoir and power steering reservoir.