Oh man... It's still having problems. When the compressor clutch is engaged things are good. The problem is, it runs about 15 min and the the clutch wont engage, not even jumping the low pressure switch works. I tapped the pulley with a hammer as I heard. Nothin, after it sits a couple of hours or over night it will work for a short while.
GOT ANY IDEAS?

 

I was having same problems and still have to get out and tap clutch to engage, I use a long 18 in rod and run it under hose so it's more straight on angle, also local a/c guy asked me when the last time i blew the dirt/dust out of radiator and condensor. Never, so i did using long air attachment, blowing from the inside out and there was a lot of dust flying. Mine still disengages but usually comes on after short bit by itself. Def helped. Also checked my air gap and it's wider than .031 in, which is the max, probably another reason field coil can't hold clutch in. Would 13 years of engaging /disengaging cause the air gap to get wider creating a lot of the, clutch won't engage or stay engaged problems?

 

Got tired of jumping out and tapping clutch to engage. Used 3/8 diameter rod and with hammer, tapped lightly around circumference of outer clutch plate. A/C has been working perfectly last four hot days. Got the idea from FSM. 8/01/12 a/c is still working awesome, now on nine days of hot. This was a unprofessional approach to solve the problem of clutch disengaging after 10 or 15 minutes, but has obviously worked. I was ready to buy new compressor or worse yet, replace evaporator core and orifice line. I did make sure high and low pressure readings were within spec and did jumper tests and swapped relays before isolating the problem to the clutch/field coil.