89 S10 Blazer a/c-constantly cycles

[airwinger]

Hello,
The air conditioning (compressor) constantly cycles on and off, on for approx. 5 seconds - off for approx. 15. Blows cold air and "feel" cks. seem ok. Had a friend put the guage to it and the freon is good. The problem has existed for it's second summer now.
The Haines manual doesn't tell me much and it doesn't appear that there is a sensor quick fix.
Any suggestions are appreciated, thanks -- Bob.

1989 S10 Blazer/4.3 litre/2WD/113,500 original, owned since new

[MT-2500]

Originally Posted by airwinger

Hello,
The air conditioning (compressor) constantly cycles on and off, on for approx. 5 seconds - off for approx. 15. Blows cold air and "feel" cks. seem ok. Had a friend put the guage to it and the freon is good. The problem has existed for it's second summer now.
The Haines manual doesn't tell me much and it doesn't appear that there is a sensor quick fix.
Any suggestions are appreciated, thanks -- Bob.

1989 S10 Blazer/4.3 litre/2WD/113,500 original, owned since new

Is this a R-12 system or converted to R-134a?
That is usually low gas or a bad pressure switch.
What was the low and high side pressure readings at idle and at 2K.
Post back pressure readings.
MT

[airwinger]

Hello MT,
The system is R12, unfortunately I don't have low and high readings nor availability of the equipment to check it again. Can you tell me where the switch is located and does it require vacating the system to change?
Thanks for your reply, Bob

[MT-2500]

The low pressure switch is on the accumulator. The big can.

If pressure is dropping below 25-26 lbs it is normal for it to shut off compressor.

But unless you just want to throw parts at it you need to check the pressure reading to see if it is the switch or just low on R-12 or bad wirng.
Also the wiring plug on the switch needs checked.

The switch just screws off and on.
There is a Schrader valve and a o ring seal to hold back pressure.

[airwinger]

Hello,
Final note for this thread - Turns out that I have a restricted dryer orifice tube -- Aww Crud!

[MT-2500]

Originally Posted by airwinger

Hello,
Final note for this thread - Turns out that I have a restricted dryer orifice tube -- Aww Crud!

If it has a lot of crud in it it may be from the compressor going out.
Good Luck.
MT