I assumed (wrongly) that there was an IRCM, based on some other internet
 searches trying to troubleshoot the A/C clutch.

My A/C compressor clutch receives no power at all, and when I read the
circuit with a digital multimeter, it appears to be an open vice off
circuit.  I do have 12V at the Clutch Cycling Pressure Switch.  The
Haynes electrical system schematic shows the 12V from the Pressure
Switch runs thru a A/C Clutch Resistor Diode to the Clutch.  I was
thinking, again wrong, that the resistor diode component must be in an
IRCM.  Additionally, control power comes from the PCM to the Resistor
Diode.  If I had any idea where to look for the Resistor Diode device
(or what it looks like), I was thinking I should be able to test it and
the PCM output as well.

I'm also wondering exactly where the PCM is located.  (In some areas
Haynes seems adequate, but in others it just adds to the frustration.)

The reason I suspect an electronic component is that after 179K miles,
two wires carrying power from the pressure cycling swith chaffed through
 to a metal brace in the eng. compartment and show shorting and
burning.   No blown fuses. Figure this fried the resistor/diode or the
PCM.  (Hot as the dickens in the mid Atlantic states right now!)

The rest of the A/C system is fine - charged with refrigerant, fan runs,
vacumn controls ok, etc.   Any info or advice on the A/C clutch circuit
would be greatly appreciated.

Thanks for replying.  HH