Drive it till it stops cooling, check and see if you are getting power to the compressor clutch. If not, find out why. If you are, replacing the clutch may or may not help.... Air gap is distance between the two parts of the clutch. (the on the belt turns, and the one that turns the compressor.)

 

I'm having the same issue with my 2001. Clutch engages blows cold for about 5-7 miles then clutch disengages. and of coarse then blows warm. I added a can of freon immediately thinking it was low. But don't currently have any gauges to read pressures.

But problem sounds similar to OP. How can I check for power to clutch?

 

For me, the problem was the signal wire that runs over the top of the air intake to the AC compressor. It apparently got too hot for it, melted the insulation and the wire was was either shorting out or breaking the connection. I spliced the wire and it's still working well.
You can measure the voltage at the compressor. Measure the voltage between the signal wire and the chassis when the compressor is on and again when it should be on but isn't working. I don't remember but I'd guess the voltage should be around 4-6 V.

 

My truck had a similar problem, turned out to be a burned out condenser fan. Replaced it and all was golden again. Check to see if that little fan is coming on at your condenser.

 

Drove all the way to Indianapolis and back. While on expressway a/c works fine. As soon as I get on surface streets is when clutch seems to stop engaging after a few miles?

 

My 01 doesn't have a condenser fan.

 

Probably low on refrigerant. Higher RPM circulates what you have better.... Grab one of the DIY cans with a gauge, and see what low pressure side looks like.

 

What should the low pressure be? and am I reading the pressure with clutch engaged or off?

 

Ran out and plugged the gauge on out of freon cans at the moment. But with a/c off clutch disengaged pressure was around 115 psi with clutch engaged dropped down to around 40psi and its around 80 degrees out.

 

Upon first issue this summer I did add a can and a half. Is it possible its overfilled and is there a way to check?