I posted this earlier and never got much in the way of constructive
advice. Now that I got things working, I thought I would post my
positive experience.

I have a 2001 2500 Cummins TD with 6-speed manual. A/C worked last fall,
now it does not. About a year ago, A/C was repaired by previous owner
(some hoses replaced) and recharged.

Clutch did not engage, indicating low pressure.

I have the manifold guages and an adapter to tap the can of R-134a. I
connected it up and the pressure was low and the same on high and low
side. I tried to charge with a can of refrigerant and the clutch on the
compressor then engaged for very short periods - a few seconds, but it
did not seem to want to take a charge.

I tried again later without the guages using one of those short (12")
recharge hoses. Did not seem to take much of the charge.

I filled a plastic container with warm tap water and stuck the can in
that. It took the charge. Compressor still engaged for very short
periods. But now it did seem to be blowing cool air! I figured this
problem is beyond me. Of course, most of you said leave this to the
professionals...

Called my mechanic. He doesn't do A/C (or diesel work). They recommended
someone local. I called him. He said if the compressor engages for very
short periods and then disengages, it is too low on refrigerant. He
wanted $135 to recharge. Said probably compressor seal is leaking and
they don't replace those, you replace the compressor. $400 just for the
part. Probably around $600 plus for the job. Probably more. Did not
chide me for putting in refrigerant myself.

So I put in most of another can. Now it works. I bought these two cans
at Wal-Mart for around $8 each. Guess I'd better carry some spares.

Funny. My 1986 SAAB 900 Turbo I bought in December 1994 from the first
owner came with all the service records. No sign of A/C repair. Two
years later It blew warm and I had the hoses recrimped and refilled with
R-12 for $150. This worked for about another 6 years and then it failed
again. I put in (gasp) hydrocarbon substitute, and recharged it again
the next year after it blew warm and it is still working!

Is it the Dodge or the R-134a system that is so failure prone? This
truck is only 5 years old!

Charles