[Shotimes] 89 SHO AC

[George Fourchy]

On Tue, 23 Aug 2005 01:56:01 -0700, Bob wrote:

>The AC clutch on the 89 SHO (converted to r134) seems to cause the belts to
>chirp on the engine.  It also seems to cycle on and off too frequently.

If there is nothing else wrong with the system, chirping just means the belt is a
bit loose.  It might seem tight, but there is a point where it will start chirping
at engagement if the belt is a bit slack.  

Normal cycling (as I remember) for an automotive a/c compressor is for it to be on
for 30 or 40 seconds, then off for that amount, then on again.  If it goes on and
off every 5 or 10 seconds, that means that either it is low in refrigerant, or the
clutch cycling pressure switch is on the way out.  The purpose of the switch, and
the resultant cycling of the compressor, is to keep the temperature of the
evaporator core just above freezing, so as not to block it up with ice.

I'm reasonably certain about the belt statement....the cycling statement is based on
what I have observed over time with functional systems, and what I've determined
from the Helms.

George