A/c

This is for a '99 3.8L...

Lat year, my A/C worked perfectly. The only odd thing about it was that if I moved the fan switch to "0" when A/C was selected on the the other switch, a loud shimmy would come from under the hood.

This year I turned on the A/C and nothing. I get air, but it's not cold. I swapped the A/C solenoid with the fuel pump solenoid and still nothing. I'm not getting the shimmy either when the fan switch is in "0".

What should I check next? How do I know whether it's the clutch or the entire compressor that is shot? The clutch spins when the A/C switch is on. Could it still be something else?

I just checked the two lines that go into the firewall and...

The thicker one mostly stays the same temp, while the thinner one becomes ice cold when I kick on the A/C. Does this mean that the compressor, pressure and everything else under the hood is ok? Should I now be looking for something under the dashboard?

I just checked the two lines that go into the firewall and...

The thicker one mostly stays the same temp, while the thinner one becomes ice cold when I kick on the A/C. Does this mean that the compressor, pressure and everything else under the hood is ok? Should I now be looking for something under the dashboard?

Not sure about the shimmy part.
But the first check on the air cond is to get a air cond recharge gauge set with both high and low gauges and get a reading on low and high sir at idle and at 2000 rmp with the air cond turned on and post back pressure readings.
The high side line should be hot and low side should be cold to the touch.
And have a good look at the compresser clutch and belt.

Do not even think about one of them Wal Mart recharge death kits
Here is a picture and link to air cond recharge gauges.
http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=66773

http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=DIY-STARTER1

http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=DIYADVANCE

If pressure was the problem, wouldn't the system prevent the compressor from kicking on?

If pressure was the problem, wouldn't the system prevent the compressor from kicking on?

We have no idea what the problem is with the pressure gauge reading.
It is not only pressure it is about having the right pressure.
As said you need to get tghe gauges on it and check it. Like this.
The first check on the air cond is to get a air cond recharge gauge set with both high and low gauges and get a reading on low and high sir at idle and at 2000 rmp with the air cond turned on and post back pressure readings.
MT

The problem went away this afternoon...weird.