On 26 Aug 2006 20:49:00 -0700, "WireSpool" >
wrote:

>PLEASE HELP!!
> I need to charge my air conditioning system but the compressor is
>not running which is necessary for the charging process. <snip>

Not really, but go ahead.

> I charged it once this spring and it worked very well. But I
>didn't put any dye in it to help find a leak, so of course it
>eventually leaked out and now needs more freon r134a. <snip>

Refrigerant containing "dye" is for lamers. It causes more problems
than it solves, including hose and seal deterioration, gumming up of
Schraeder valves, plugged expansion valves and on and on. Don't use
"dye" refrigerant. Poop Boys sells and promotes that crap, I believe,
so they can sell more compressor swap jobs out in the shop. The only
way to do a good leak test is with a proper halide detector. Small
leaks may need application of dry nitrogen to boost system pressure to
find them.

>This time I was
>going to put the dye in but I'm stuck because the compressor is not
>running. I'm pretty sure it's cause the low pressure switch is not
>allowing it to run. In my Haynes book it says that this is not uncommon
>and is easily taken care of by unplugging the low pressure wire plug
>and jumping the wires and the compressor will run continuously allowing
>me to fill with freon. The ONLY trouble with this whole thing is that
>they don't show me where and what this plug looks like. The last thing
>I want to do is start crossing wires and short something out.
> If anyone can help I would greatly appreciate it. <snip>

First, you don't say what car/system this is, so I'll assume it to be
a Chrysler H-block layout. If so, the low cutout switch is on the
H-block itself, a rubber 2 conductor plug...NOT the evaporator
thermostat, which is downstream on the suction side.

First, you obviously have a leaking system, and you're probably
already short of oil. Second, since the compressor's already cycling
due to vacuum on the suction side, there's a better than 50/50 chance
the system is contaminated with air and moisture, which is death to
any refrigeration system.

Take the car to a licensed tech and do it right the first time. I've
seen dozens of compressor failures/contaminated systems from people
getting those infernal "cans" at Poop Boys or similar and a cheapie
charging hose. Since 134A doesn't have the same oil miscibility as
12, oil level in the system in crucial to compressor survival. Second
in line is owners who add the wrong viscosity oil, or the wrong base
stock. Want to see a compressor fly apart? Just put some mineral
base stock refrigeration oil in a 134A system! If you do not have a
good vacuum pump that'll pull at least 100 torr, you can't do a good
job of purging/charging a system anyway.

Don't goof around...take it to a good shop, or your repair bill will
get larger as time goes on..