Automotive Air Conditioning Information Forum

2006 PT Cruiser, history unknown, bought recently. System not cooling, compressor running and cycling, decided to start fresh.

Pulled a vacuum for half hour, let it sit for another half hour, holding perfect vacuum. Put in a can of refrigerant, which is 2/3 of the stated 1.125lbs capacity. Ambient is about 65F. Compressor cycles about 10s on and 10s off, during which the low pressure side goes back and forth from 20 to 40psi, slightly more each time. The high side goes up steadily (no ups and downs) with each cycle, until it reaches 400psi. At that point the low side is about 50. Then the compressor goes off, the fans come on, pressures both drop to 20/100 and the whole cycle starts again. But on the second big cycle, it reaches close to 450psi on the high side, at which time I shut it off so it doesn't blow off. After it's off for half hour, pressures are both at 80psi.

Any ideas? Partially clogged orifice? Thanks for any advice.

At least one of the fans should be running with the A/C compressor. Some systems run both fans at lower speed.

With no airflow on the condenser until you hit 400+ psi, you will have odd results.

Find the electrical issue keeping you from having fans on with the compressor running.

Yes, thank you, I mis-spoke but you are absolutely correct.

The PT Cruiser has one 2-speed fan. What I meant to say is that I heard it kick into high when the pressure got over 400psi. I neglected to notice that it was NOT on low before that. Turns out the low speed winding is dead. You can't see the fan and it's pretty quiet on low so I failed to notice it wasn't coming on with the AC.

Much appreciated. I will change the fan and report back.

My sister now has my mom's 2005 PT Cruiser (Las Vegas) and the AC in it works good. So there's good chance for you !!