evaporator freeze up

What are some possible causes for the evaporator to freeze up? 97 z-71 350

--
also every once in a while the heater will come on on its own I cant shut it
off even with the a/c on or just the blower motor and vent on it will still
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lack of refrigerant

it
still
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thanks What should the low pressure read if the ambient temp is 91 degrees
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don't have the gauges in front of me, but a minimum of about 40 psi on R-12 system, 45 on R-134A should be as low as you'd want to see

degrees
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Your clutch cycling switch is stuck in the closed position. You can change it yourself. Un plug it Unscrew it Therer is a schrader valve in the fitting it is screwed on to. screw on the new switch, plug in the wires.
: > What are some possible causes for the evaporator to freeze up? 97 z-71 : > 350 : > : > -- : > also every once in a while the heater will come on on its own I cant shut : it : > off even with the a/c on or just the blower motor and vent on it will : still : > blow hot air . : > : > : > : :
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Actually plenty of refrigerant. The receiver/drier is on the Liquid side (suck side) of the A/C system, that aluminum cylinder gets quite cold. With the dewpoints we've bee nseeing the past week you can build up a lot of ice around the accumulator. Have a great one!
Bush
On Fri, 25 Jul 2003 12:39:06 -0400, "Gary Lawrence"

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