A/C Myster - 2003 Saturn VUE


I posted the below a few days ago - but there I discovered a few NEW clues… could use some advice.

I have a mystery for everyone - help if you can!

I own a 2003 Saturn VUE (4-Cyl Manual). The A/C works perfectly when the engine is running and at a stand-still. It works perfectly while moving as long as it is less than 20 MPH. Any speeds above 20 and the A/C no longer produces cold air. I have road-tested and found that the RPMs don’t make a difference, but the speed of my car does.

A little background:

I was in a wreck about a year ago (during winter) the first warm day after this wreck is when i noticed this phenomenon). I don’t think it is a refrigerant leak as the A/C has continued to do this for over a year now. I was told by Saturn that I needed a new compressor - but it would cost over $1000 because they quit using the type I have in 2003, so a conversion to the new one would be required. I was told by someone else that it might be vac. related.

Also - during my last service at Saturn they told me my battery would need to be replaced soon as I was not getting a full charge or not enough Amps or something along those lines.

HELP! What is wrong with my car?

NEW CLUES - I poked around under the bonnet and found that there are two wires SUPPOSE to be running into the Thermal Expansion Valve area, that are torn loose from the firewall. Not sure what they are for, but wondering if that could be a source for the problem.


   Dealers are no better (or worse) than independent mechanics for almost anything you might need done on your car.  They will almost always charge more per hour and often more for parts and supplies.  They also tend to look at repairs a little different than the independent. 

A dealer may well recommend work that strictly may not be needed, but could be connected to the problem or maybe replace a part when a little repair would fix it ALMOST as good a new.  

There is no need to bring your car to the dealer for any service other than service that is going to be paid for by a recall or original warrantee. 

I suggest that most people would be better off finding a good independent (Not working for a chain) mechanic.  

This compressor story just does not sound right to me.  As I recall manufacturers are required to provide replacement parts for a given number of years, I seem to recall it being seven.  Also the problem does not sound like a compressor issue to me.  It does sound like a loose or disconnected vacuum line. 

Find a local [b]independent[/b] A/C guy.  Look at the radiator shops.


I’m going to bank on the electrical problem. As you go faster, the vehicle’s systems begin to require a little more power to feed and cool the engine. It’s not much, but you may be on the line between having enough voltage to create a stable strong field and keep the compressor engaged, and not.

Nail down the electrical problems. Ensure that you’re getting around 14v at all RPM with the engine running. See if that does the trick.



I also doubt the compressor is bad since it works ok part of the time at least. There is a pressure valve that stops the cooling process if pressure gets too high. With the compressor going over a certain speed it may be over pressuring the system.

Another possibility is there is a vacuum leak and the air blend door is changing due to a lack of vacuum and the heater core is being selected. If the cooling comes back almost as soon as the engine speed goes down then I would suspect the lack of vacuum for the blend air door.


This site may help:


Search/post in the Vue Tech forum. Some Saturn Techs post there. It is free. As someone I know once said, if it is free, it is for me…