Re: 4kQ: A/C question ...

[Luis Marques <marques@ti.com>]

Steven: There is nothing wrong with your A/C.  This is the way it's
supposed to work.  The compressor doesn't work more or less as you
change the temperature setting or fan speed, but rather stays on for
longer or shorter periods of time as it cycles.  I'm sure there are
other A/C experts on the list (I'm not), but basicly the A/C refrigerant
gets cold when it expands thru the expansion valve right before the
evaporator under you dash.  For this, the compressor must build up the
pressure in the system and that's why it gets harder and harder to
turn.  So reconnect that wire in the compressor and enjoy the cold in
these hot summer days :) 

Luis Marques
'87 4kcsq

steveb@falcon.kla-tencor.com (Steven Buchholz) wrote:
> I don't often use the A/C on my cars, so I just recently tested the 
> system on the '85 4kQ that I bought.  I had noticed that whenever I 
> turn on the A/C I hear the compressor click on, stay on for a few 
> seconds and then  click off, and then stay off for a few seconds, then 
> repeat.  For safety's sake I disconnected the wire to the compressor 
> clutch.  Well, I put a pressure gauge on the "low side" of the system 
> and it seems like the system has a good charge.  I then tried turning 
> the compressor by hand (engine off) at first the compressor turns 
> rather easily, but it gets more difficult to turn quickly, finally 
> becoming nearly impossible to turn by hand.  I did not expect to 
> observe this behavior when turning by hand, so I'm thinking that there 
> may be something plugged like the expansion valve.  Can anyone confirm 
> this or point me in another direction on this one?  TIA!