need some help guys.. my car blows air but its not cool at all. I think i ran out of freon and the car tripped the compressor off for some reason. This all happened over night. the a/c pulley is turning but the clutch is not engaging the compressor. I have heard that in some cars you can follow the electrical line out of the back of the compressor until you find a clip and trip the switch to turn the compressor back on.. does such a thing exist in our cars? if so where is it?

I tried refilling the freon but since the compressor is not running it would not take in any..

Also, i can not run my a/c at full blast. when i turn it up past about the "3" setting it just stays at the same speed..

So any help is much appreciated I am really trying not to take it into the shop to have it repaired..

 

There may be a final stage relay for the fan. I know this is a common problem on some BMW's but not sure about our cars.

 

Not sure on the Crossfire but many cars will not cycle the compressor unless there is enough freon pressure. On my son's Mitsu I simply found the wire going to the solenoid that runs the clutch, disconnected it from the harness, spliced in 12 volts and added freon. Reconnected the wire to the harness and everything works great!

 

First I have to ask why you think you lost freon? If you lost enough for the "low pressure" switch to open, then you need to make a repair.

Charged cans of freon will go in a low system without it running - slow but it will go in. Holding the can upside down so liquid goes in will work until the clutch engages. If you put two cans in and the clutch still does not cycle, chances are you have a different problem.

You really need to invest in a cheap set of gauges if you plan to do some occasional AC work. I have worked on many AC systems, just not had to mess with my Crossfire to give you exact details.

If the system is completely empty, not just low, you really need to pump (vacuum) the system down to remove any moisture/humidity. Refill with the correct amount of oil and freon.

Chances are that the PCM or BCM is controlling the AC clutch (relay) depending on the pressure readings it is getting. I would not suggest jumping any 12v to anything without studying a wiring schematic/diagram.

As for the blower on most cars, usually "high" runs on a relay to give the blower motor full voltage. Any speed below that runs through a module or resistor block to slow the motor down to the desired speed. Again, sorry I can't give exact details for the Crossfire.

Maybe someone else can chime in with more details.

James

 

If the refrigerant leaked out overnight then it would be a waste of time and money to put more in. That's like putting more air in a flat tire before you fix the puncture.
Chances are it did not leak and you have another problem, disconnected wire at A/C clutch, bad clutch, fuse etc? Too much refrigerant is not good either.
Look at the workshop manual for clues.
There are threads here that deal with the fan control.

 

What james said, also the clutch could have bad, the relay as well, the wire to the clutch could be grounded or, or shorted somewhere.

With all the different modules that control everything in this car, its hard to say exactly what could be the problem.

If you have a leak, its best to fix that before you start diagnosing the clutch issue

 

First of all I would check to see if the system has pressure, then go from there. No pressure means leak in system, pressure means something else most likely electrical of some sort. There are a lot of sensors now days on a/c systems for example if your outside temp is reading minus 40 degrees or your coolant temp sensor is off ( not reading correctly ) this can send signals to the ecm and not allow the a/c clutch to engage ( ecm thinks it to cold to have a/c on ) so checking the pressure is first, and as the fan speed goes, I think you are going to need a new fan controll module ( blower risitor )

 

To find the problem it is a good idea to study the Heating/Air Conditioning section in the Shop Manual. A good digital Multimeter is a good thing to have when checking the ohms, volts etc as some of the readings are very low and will not show up on the normal analog meter.

If you cannot check the circuits out it is really hard to diagnose some problems over the forum, guesses could be way off and if you do things that are incorrect then you could add further problems.

 

Hello. This is an older thread, but I'm sure this happens more and more now that the cars are getting older. I had been having a similar problem, and I fixed my intermittent AC clutch problem by using a little oil on the clutch. I recharged the AC and had the same result, the clutch did not engage.

The AC was coming on when driving on the highway, but not engaging when city driving or idle.

I almost bought a new compressor today, and made an appointment to have it looked at (I get to cancel that now!) when I decided to put a drop of oil on it. It started right up, so of course I put MORE...and no I didn't get it on the belt.

So if you're having an intermittent problem like this, try a little WD40 or a garage door oil.

So we'll see how long this lasts, but for now it worked. I will update if it remains functioning or if it changes.

 

When the car runs out of Freon the low pressure kicks the entire system off to protect components. You can cross the wires on the low pressure switch and the system will come back on. If that works replace the low pressure switch. Just guessing as I can't see the car. When you cross the wires on the low pressure switch you can put more Freon in as the compressor should come on.
Ken

 

Disclaimer... Only people familiar with A/C systems should work on them. They are dangerous to life, limb, and property if mishandled or abused.

READ THE ONLINE (OR PRINTED) SERVICE MANUAL CAREFULLY! Be careful adding Freon to this or any A/C system. If you KNOW the Freon leaked out and it is almost totally empty, find and fix the leak (don't leave the system open to atmosphere any more than necessary), and buy three of the 12oz cans of R-134 (some of the compressor/system oil may have leaked out when the leak occurred so use your best guess on getting one of those R-134 12oz cans with compressor oil included in it, don't add too much compressor oil as it is just as bad to have too much throughout the system). DO NOT RUN THE COMPRESSOR UNTIL YOU VENT AS MUCH OF THE AIR/MOISTURE OUT OF THE SYSTEM AS POSSIBLE BY PUSHING IT TOWARDS THE OTHER ACCESS FITTING WITH THAT 1st (STRICTLY GAS) FREON CAN ON THE LOW PRESSURE SIDE. Use about 4oz of this one can to vent the air/moisture out of the system SLOWLY, I repeat SLOWLY (of course almost every state/jurisdiction makes self service of A/C systems/venting of Freon ILLEGAL so be warned). If you do not displace ALL the air/moisture that may be present inside the system you'll ice up the needle valve/expansion valve and it will not function properly (short cycle). NEVER add Freon to the high pressure side of an A/C system. Always add to the low pressure (gas) side as the liquid line side is of a very high pressure, especially just after shutting off AND anytime the compressor is running. Its specified total capacity is slightly under 2lbs of R-134. Overcharging the system makes it unsafe and prematurely wears out components like the compressor, evaporator, D/X coil and fittings/lines. Finally, please remember the compressor may kick on/off based on a number of sensed conditions and should be treated like it could kick on at any time (which is why you should never hook up a refill to the high pressure liquid line side). Before you post a reply, the fittings sizes are different, you would be surprised how many make an adapter to use the 12oz and 16oz cans of R-134 and access the high pressure side at the front grill location in auto systems. I have seen what the high pressure side of an auto A/C system can do to one of those retail refill cans. They are not designed to handle the very high pressures associated with that liquid line. Please be careful!