Understood fellas, thanks for all the info.  I'll have it fixed up
this weekend.

Yep - three years is not good. A professional will evacuate the old
refrigerant for reuse, and will pull a vacuum on the system to remove
incondensables and water, and to test for leaks. Leaks have to be fixed
before recharging.

Mike

Leakage of refrigerant in cars is a common occurrence.  It's the *rate*
of leakage that can be of concern.  "Topping off" every three years or
so is (to me) the benchmark for action should it occur quicker than that...

JT

The car is a 1999 (made in '98) so would you expect that there is a
leak in the system?  The coolant doesn't just evaporate over time,
does it?

I will check into have it recharged, but I'm wondering if it might
just leak out again.

Thanks a lot!!

Dang - I missed that point the first time I read it. "Every second or so" is
a big red flag for low refrigerant. Time to take a trip to an auto A/C
professional. R-134a is tricky stuff to try to recharge yourself, although
at this point I'd venture the total charge is just a few ounces.

Mike

A low refrigerent level can cause short cycle times.

JT

    I'd brought this up a couple weeks ago, but wanted to run it
by y'all again with different wording.

    Sometimes, maybe 1/3 of the time, when I'm stopped at a red
light, and only when the A/C is on, I notice my RPMs just going up a
couple hundred, down a couple hundred every second or so as my A/C
compressor clicks on and off.... click, click, click, click... on,
off, on, off...

Click... rpms go up as the compressor turns on
Click... rpms go down as the compressor turns off
Click... rpms go up as the compressor turns on
Click... rpms go down as the compressor turns off
Click... rpms go up as the compressor turns on
Click... rpms go down as the compressor turns off
Click... rpms go up as the compressor turns on
Click... rpms go down as the compressor turns off
Click... rpms go up as the compressor turns on
Click... rpms go down as the compressor turns off

    Over and over.  I don't seem to notice it much while driving,
just at stops.

    What do you think the issue is?  Vaccuum leak?  Bad
Compressor?  I want to have this looked at, any idea what that should
run me at the mechanic?

    I'm asking again because I did have a bad A/C control unit
(the box next to the radio that controls fan speed, temperature, etc).
I just replaced that unit today.  While it fixed the problems of knobs
that didn't work anymore, I wanted to make sure it was not related to
the click click click click issue above.

    Thanks!