I have a 94 SL2 Saturn and the A/C is not working. I press the A/C button and turn the knob on the fan, and all I get is warm air. The A/ C light comes on, but I don't feel any load on the engine. I have looked under the hood and I the A/C clutch does not engage. The last thing I want to do is take it to a mechanic. I know some about cars and feel comfortorble doing the work myself. But I have never had this problem before. How do you recomend diagnosing the problem? The fuses and the relay seem to be fine. Nothing obvious from just quickly looking at A/C compressor or A/C lines. Any help greatly appreciated...the heat is climbing here!
Generally speaking if your AC clutch will not engage and the fuses and wiring is all OK, then it is a sign that your AC refrigerant is low. There is a pressure switch that completes the circuit and does not allow the compressor to engage when the refrigerant is low. This is to protect the compressor from self-destruction since the refrigerant/oil mix is what lubricates the compressor.
My guess is that you have a leak. The only way to determine the source will be to recharge the system with a leak detecting refrigerant and then use either an electronic sniffer or a black light to find the leak. The source of the leak will then need to be properly repaired mechanically, the receiver/dryer will also need to be replaced. The system will then need to be evacuated and tested to assure it holds the vacuum for 24 hours, before it gets refilled with new refrigerant.
This is typically a fairly expensive process which requires the proper knowledge, tools and test equipment. I would not recommend that you try this yourself! Unfortunately, the cost of this repair depending on the component that needs replacement could easily exceed the value of your vehicle.
Agreed. A lot of things a DIY'er can do but the A/C system is not one of those things. It's probably has a small leak, if your lucky its a simple seal and not a unit. A 94 should have 134a which is a plus. A shop can put some refrigerant in (hopefully they check for contaminants) and check for leaks and then upon finding the leak(s), "recover" the refrigerant open the system up, replace the leaking unit or seals, replace the receiver dryer, add pag (double end capped hopefully), vacuum and recharge the system. If its an easy leak to fix like a seal it should run you about $150 bucks tops. Or you could get MVAC 609 certified and spend about 5 grand on 134a equipement to do it yourself...
I know I'm going to get shot for this and called a bunch of names by some on here, including text in big caps urging you not to do this by some, but you can take it or leave it...
I had the same car (well, a '94 SL2) up to about a 1-1/2 years ago with the same problem...After the winter, got no AC. There was a charge in the system, but when it gets too low, it won't let the compressor kick in. What I did for the 4 years after discovering the no AC issue was I went down to AID Auto stores and picked up 2 cans of 134a refrigerant for a couple bucks each. If you don't have one, for about $20 you can buy the "charger" which is essentially a hose with a coupler to the can on one end, a coupler to the car on the other with a gauge in the middle and throw the charge in yourself for a total of around $25-30 bucks the first time, and under ten each year after. I originally did mine to determine if it was a low charge or if it was something major. Hooked the charge up, turned on the car, turned the AC on max and opened the nozzle. The compressor kicked in and I charged until the gauge was in the green and, vola! - I had nice very cold AC, then disconnected. Now, I obviously had a small leak that my charge would last all summer - yours might be different and be gone in a month, day or week in which case, buying cans of 134a will quickly add up to the "getting it done right" method, but it'll at least tell you what your working with.....
...and before anyone jumps on my case here about doing this, it's a 13 year old car.... and as was mentioned to take it someplace to get "properly" fixed will be costly. It's not a big deal and doesn't take a rocket scientist to charge a system. However if it was a newer car, it would be well worth the money to take it in and do it right per what was written to you below. But your car's worth to anyone but you probably is going to equal the cost of the fix..........Your choice...Good luck and post what you ended up doing....
It all depends on the size of the leak! As someone else pointed out, it could be as simple as needing a new O-ring and/or tightening a fitting. Most times it is not that simple though and a couple cans of refrigerant will make it work for a few days (or less).
Doing it the way you suggest is not good for the environment and may not be for your pocket book either. If you do elect to go that route, use a can of the refrigerant with the leak locating dye!
Again, post what you find to benefit others and best of luck.
That's why I said that I obviously had a small leak in which (2) 12oz cans lasted me from June through whenever (as of September it would still work and must have gotten low between then and the following June) This method was cost effective for me as I already had the charger, and it cost me $5-10 each June to have AC for the summer.
I agree with using the locating dye refrigerant though....especially if he does it this way and the AC only lasts a short time, it'll tell him where the leak is. My point is that if he did it this way he would know for relatively little money what and where his problem is. If the compressor doesn't kick in, then he knows he's probably got other more costly issues, but he can make the call then if he wants to drop a few hundred or more bucks, sweat it out for the summers or get another vehicle - but he'll be able to make that call for about $25 and 10 minutes of his time....As far as the environmental thing, he's not dumping 4 quarts of oil in the dirt behind his garage and I can pretty much guarantee you that he's not going to be putting in refrigerant every day, week or month as that would be ridiculously stupid as it will quickly add up to just having it fixed. But on a 13 year old car, if he puts a couple of cans in now and they last him the whole season, he'd probably be happy.
Thanks for all your advice! My buddy has a 134A charger hose and I will buy a couple of cans (the ones with the dye ink sound good) and go from there. If it takes just a couple of cans per summer I will be happy. As for the environment issue...well I don't think the car will last more than a couple of years anyways. It is just a college car. I'll let you know how it all goes.
If you have access to an A/C vacuum pump, then you could alternatively evacuate the system and see if it holds the vacuum for just 1 hour or longer. If it holds the vacuum reading for 24 hours, then you may be able to get by with a simple charge.
In any event, good luck and do let us know how it goes.
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