a/c unit runs but does not cycle on and off

[NastyStang]

Hey All,
I recently had my a/c stop blowing cold air, So i bought a set of gauges vacuum pump new dryer liquid line/w orfice.
I installed everything and now my compressor will not cycle off it just runs all the time.
But first it would not come on so i took off the cycle switch plug and jumped it to see if the compressor would work but no luck.
then I went to the a/c unit and unplugged the wire to it and checked it for voltage 0 nothing
plugged it back in and went to the fuse box but found nothing.
So i went to the control switch for the a/c and turned it off on a couple of times
went back to the cycle switch and pulled it off and on.
then all of a sudden the a/c clutch turn on and cold air was coming out of the vents.
But now the clutch does not cycle off it just keeps running
Now is the switch on top of the dryer the cycle switch or a high pressure switch?
The other switch in question is the on just after the condenser is that the cycle or high pressure switch?
everything was working fine before i messed with it
not sure what to do next?
HELP anyone?
the low side pressure was reading about 40 and the high side was about 200

 

[NastyStang]

A/C compressor does not cycle off

just replaced dryer and orfice line new oring syst5em held vacuum good added 2 and 1/2 cans of 134a
now compressor comes on but stays on
it blows cold air
the low pressure was at 40 on the 134a part of the gauge
the high pressure was @ 200 on the psig part of the gauge
can i use the cycle switch off of my 90 gt? to test before i go and buy one?

 

[Tbuck07]

Re: A/C compressor does not cycle off

Yeah,

Not sure what your cars problem is but theres absolutely no point in posting two topics with the same question in them, with different titles.

 

[modo]

Re: A/C compressor does not cycle off

if the car came with r-12 and you installed 134a you will have to change the regulator which cycles the compressor since they operate at different pressures. on the fox bodies there is a cap covering a pressure sensor on the accumulator tank. a 1/4 turn counter clock wise would do it.

if the sn cars came with 134a ignore everything i said

 

[toyman]

The cycle switch is on the top of the drier. I don't know what the low side pressure is supposed to be but I would guess that you may have over charged the system. From the Ford service manual here's how it works.

"The A/C cycling switch (19E561) is mounted on a Schrader valve fitting on the top of the suction accumulator/drier (19C836).

l A valve depressor, located inside the threaded end of the A/C cycling switch, presses in on the Schrader valve stem.

l This allows the suction pressure inside the suction accumulator/drier to control the A/C cycling switch operation.

l The electrical switch contacts will open when the suction pressure drops to 152-193 kPa (22-28 psi).

l The contacts will close when the suction pressure increases to 276-324 kPa (40-47 psi).

l Ambient temperature below approximately 7-10?C (45-50?F) prevents the A/C cycling switch contacts from closing.

l This is due to the pressure/temperature relationship of the refrigerant and the requirement of the system pressure to reach 276-324 kPa (40-47 psi) to close the A/C cycling switch contacts.

l These contacts control the electrical circuit to the A/C clutch field coil (2987).

l When the A/C cycling switch contacts close, the signal to energize the A/C clutch (2884) is sent to the Constant Control Relay Module (CCRM).

l The CCRM then supplies the voltage to energize the A/C clutch for A/C compressor (19703) operation.

l When the A/C cycling switch contacts open, the CCRM opens the A/C clutch electrical circuit to de-energize the A/C clutch and A/C compressor operation stops.

l The A/C cycling switch, will control the A/C evaporator core pressure at a point where the plate/fin surface temperature will be maintained slightly above freezing.

l This prevents A/C evaporator core (19860) icing and the blockage of airflow."