Low on refrigerant is usually it.

 

You could send it to charm school to become more engaging.
I'll be here all week folks.

 

Low on refrigerant is usually it.

Besides taking it to a repair shop, anyway to test the gas level?

 

Auto places sell cans of refrigerant with a gauge on them.

 

My 1995 Astro recently stopped cycling it's A/C clutch, it has R-134a, and plenty of it, but will not cycle. Where should I start?

 

My 1995 Astro recently stopped cycling it's A/C clutch, it has R-134a, and plenty of it, but will not cycle. Where should I start?

How much pressure is in it?

 

x2 w/ Chev

I believe the low side pressure needs to be around 44 psi for the compressor to kick in (or maybe that's my Jeep, can't remember). So, like Chev said, grab a cheapo R134 refill kit at the Autobone or which ever LAPS you have and get to measuring! BTW- Make sure you get the kind that has refrigerant AND oil.

Here's an example on Amazon...
http://amzn.com/B001810SHA

This guy did a pretty decent write up on Yahoo Answers...
https://answers.yahoo.com/question/index?qid=20060718155308AAjfrPU

 

Thanks for the link, I will check the pressure tomorrow.

 

The pressure on the low end side is quite high - around 110 psi. What should I do next?

 

Test the low pressure switch and see if it is closed.

 

I took the switch off and checked it, it is open, and inserting a jumper wire in the harness connector for the switch did nothing.

 

Any idea as to where I should check next?

 

THAT, ladies n gents, is the extent of my AC knowledge... sorry goat. I have never heard of low side pressure that high in any system... sure you're on the right port? If so, you might just have a service done. They vacuum the system, replace the receiver/ dryer and refill the system, bring everything back into balance.

 

I took the switch off and checked it, it is open, and inserting a jumper wire in the harness connector for the switch did nothing.

When you say you took the switch off. Do you mean unplugged it and left it attached to the system. or took it off.
Anything above 30-40 lbs in the system and it should be closed. test is invalid if you took it completely off. It should always be open if there is no pressure.

 

He's asking if you unscrewed it or jumped the wiring connector?

That's the connector - did you unclip the connector and put a piece of wire (or a paperclip) in both of the pins? If you did, and the AC won't run, the pressure cycling switch isn't the problem.

 

Well illustrated, thanks Leeann,

 

He's asking if you unscrewed it or jumped the wiring connector?

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That's the connector - did you unclip the connector and put a piece of wire (or a paperclip) in both of the pins? If you did, and the AC won't run, the pressure cycling switch isn't the problem.

I unclipped the connector and placed a wire into each of the pin holes, the compressor did not cycle.

 

110 psi in the system on the low side is normal if the system isn't cycling coolant...you'd see the same pressure on the high side as the system is equalized. With the system running, the low side should be around 35-45psi depending on temp and the high side should be somewhere in the 200-250 neighborhood...again, depending on ambient temps. If the high side is in the 300's, then you aren't getting proper cooling through the condenser or you have an orifice tube problem.

The fact that you see 110 psi means you should have enough pressure in the system. To me, it sounds like you have a dead A/C clutch. Of course, this is all assuming that you are getting power supplied to the clutch via the paperclip jumper. Keep the jumper in, and then test for voltage at the compressor clutch switch. There is a high pressure switch in the back of the compressor, but that is designed to shut the compressor off if it exceeds the high pressure limit.

 

In the dash in the heater controls there is a electrical switch that powers the clutch before it goes through the low pressure switch etc. Test to see if there is power getting to the low pressure switch.

The contacts get hot melt the plastic and it looses power. It is the selector switch so the compressor has power in def, bi-level, and A/C functions and not the heat ones.

 

110 psi in the system on the low side is normal if the system isn't cycling coolant...you'd see the same pressure on the high side as the system is equalized. With the system running, the low side should be around 35-45psi depending on temp and the high side should be somewhere in the 200-250 neighborhood...again, depending on ambient temps. If the high side is in the 300's, then you aren't getting proper cooling through the condenser or you have an orifice tube problem.

The fact that you see 110 psi means you should have enough pressure in the system. To me, it sounds like you have a dead A/C clutch. Of course, this is all assuming that you are getting power supplied to the clutch via the paperclip jumper. Keep the jumper in, and then test for voltage at the compressor clutch switch. There is a high pressure switch in the back of the compressor, but that is designed to shut the compressor off if it exceeds the high pressure limit.

I know this will show my lack of knowledge, but where is the compressor clutch switch located at on a 1995 Astro?

 

The electrical connection right behind the pulley on the compressor. There isn't a switch per se...it's the collection of low and high side sensors and the A/C switch on the dash working together to send voltage to excite the magnet in the compressor clutch to engage the compressor. Usually, bypassing the low pressure sensor as seen previously will engage the clutch regardless of system charge. If it will not, then either there is a voltage problem, or a clutch problem.