Air Conditioner lines freeze - why ??

[CREWZIN]

I'm not 100% positive but when they changed mine out (twice - first one was tightened too much and squashed the rubber O ring so they had to replace it again) they didn't seem to lose any Freon while doing it.

[calflan]

Thanks alot crewzin !

[slartyblarfast]

High pressure switch and clutch cycling switch are 2 different animals. The cycling switch is on the low side on top of the accumulator. The high pressure switch is on the back side of the compressor. High pressure switch will not cause freezing. Cycling switch will because is doesn't turn off the compressor and the evaporator gets too cold. The accumulator is the aluminum cylinder close the the firewall. Don't have a pic, sorry.

[quintas]

If any switch is going to cause freezing it will be the low pressure cycling switch.
The high pressure switch is just that - a protective device against
extremely high head pressure. Freezing is a result of extreme low pressure.
Another cause of "ice up" could be a restricted expansion valve or orifice.

[CREWZIN]

Wow, we must be really confusing anybody who's reading these threads. The picture I posted on the #3 post points to a high pressure switch on the accumulator which is the one that caused my system to freeze up. The picture that was just posted says the same switch on top of the accumulator is the low pressure switch whereas slartyblarfast just posted that the same switch is a "cycling switch" (not high or low) and it's a different than the High or Low switch and that the high pressure switch is on the compressor.

[quintas]

The clutch cycling switch is commonly referred to as the "Low Pressure Cut Off Switch". It is always located in the low (suction) side of the system, usually right on the accumulator. It prevents freezing and controls air temperature coming from your dashboard outlets by cycling the compressor clutch on & off according to low side pressure. If it sticks in the closed position your clutch will not kick off, and the unit will freeze up. Turning the a/c off should de-ice it but after a while it will freeze up again. Keep in mind, this is all true assuming the switch is actually bad.

[TexasPriest]

I too have this very same problem with my 2006 PT. Earlier this week I had the PT in for routine servicing and asked them to looking the AC issue. They told me it was a switch but didn’t provide any details. Because they had to order the part, and it was gonna take a few days for the part to arrive, I picked up my car and have been driving it. The AC has been working perfectly since I picked it up! Right now the Chrysler guy is trying to schedule an appointment to fix the AC. They have quoted me a repair cost of $200. Reading this thread I am now questioning the cost of the repair. But this thread is also a little confusing! So I have a couple or three questions.

What is the name of the part? Low Pressure Cut Off Switch (aka Clutch Cycling Switch)? Or High Pressure Switch?

Is there a link with replacement instructions?

Is this a part a Semi-Novice can change? I can follow instruction well. Are there any items I need to be concerned about? Like loosing coolant.

Why do you think the AC is working now? Could the recent AC servicing and troubleshooting have knocked the switch loose?

Thank You!

[TexasPriest]

Originally Posted by TexasPriest

I too have this very same problem with my 2006 PT. Earlier this week I had the PT in for routine servicing and asked them to looking the AC issue. They told me it was a switch but didn’t provide any details. Because they had to order the part, and it was gonna take a few days for the part to arrive, I picked up my car and have been driving it. The AC has been working perfectly since I picked it up! Right now the Chrysler guy is trying to schedule an appointment to fix the AC. They have quoted me a repair cost of $200. Reading this thread I am now questioning the cost of the repair. But this thread is also a little confusing! So I have a couple or three questions.

What is the name of the part? Low Pressure Cut Off Switch (aka Clutch Cycling Switch)? Or High Pressure Switch?

Is there a link with replacement instructions?

Is this a part a Semi-Novice can change? I can follow instruction well. Are there any items I need to be concerned about? Like loosing coolant.

Why do you think the AC is working now? Could the recent AC servicing and troubleshooting have knocked the switch loose?

Thank You!

IS this the part? AutoZone.com | | A/C Clutch Cycling Switch | CLUTCH CYCLING SWITCH

[neon95]

got the same problem in the wifeys neon its the h/p switch makes the ac run none stop. makes it hard on gas as well

[quintas]

THE LOW PRESSURE SWITCH ON THE ACCUMULATOR HAS IT'S OWN SHRADER VALVE AND CAN BE REPLACED WITHOUT DISCHARGING THE SYSTEM. SCREW ON, SCREW OFF.

CAUTION!!
THE HIGH PRESSURE SWITCH IS UNDER PRESSURE AND HAS NO SHRADER VALVE. THE SYSTEM NEEDS TO BE DISCHARGED BEFORE YOU CAN REMOVE IT! (NOT RECOMMENDED FOR NOVICE'S)