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Hooked up gauges to my AC and then noticing that the low side is high actually pinned, and the hight side is about 250. What could cause this? AC works for about 15 minutes 20 minutes then blows not hot and not cold air if I shut it off for 3 minutes and turn it back on it blows cold air again.
From the shop manual:
Normal Pressures for the AC lines are Low Side: 21.3-42.7 psi and High Side: 199.1 to 270.2 psi
Your high side seems fine, so working from the manual on low side:
Symptom: Suction (Low Abnormally High. Gauge) Pressure Low pressure gauge (Low pressure gauge is lowered after condenser is cooled by water.)
Cause: Excessive Refrigerant In System
Fix: Discharge and Recover, Replace Coolent to recommend levels
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Symptom: Suction (Low Abnormally High. Gauge) Pressure Low pressure hose temperature. (Low pressure hose temperature around the com compressor ressor refrigerant line connector is lower than around evaporator.)
Cause: Unsatisfactory valve operation due to defective temperature sensor of expansion valve.
Fix: Replace the expansion valve.
Cause: Expansion valve opens too long.
Fix: Replace the expansion valve.
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Symptom: Suction (Low Abnormally High. Gauge) Pressure High and low pressure gauge balanced quickly. (After turned off A/C)
Cause: Compressor gasket is defective.
Fix: Repair or Replace Compressor
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Symptom: Suction (Low Abnormally Low. Gauge) Pressure, Insufficient cooling.
Cause: Insufficient refrigerant in system.
Fix: Check for leaks. Discharge and recover the refrigerant. Recharge to specified amount.
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Symptom: Suction (Low Abnormally Low. Gauge) Pressure, Frost on the expansion valve inlet line
Cause: Expansion valve clogged.
Fix: Replace the expansion valve.
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As you can see, there are a lo trof variables. A/C systems should be checked by a certified A/C mechanic.