2002 l300 sedan v6 AC blows warm, compressor engages...

[dbinteract]

Anyone have some thoughts they can share with me?
My 2002 L300 Sedan AC is blowing cool, warm air.. but definitely not cold.
The compressor was not engaging, I jumped posts 30 and 87 to get it to engage, and checked pressure, it was low, so I added refrigerant, and got pressure to where it should be. took the jump out, and put the fuse back in.. the compressor is now still engaging.. I thought GREAT I have it fixed.. but no, I am still getting warm to not quite cool air coming out of it.

Also, I am curious the fan speeds... The AC only stays on with the first 3 speeds, if I turn the fan full blast, it shuts the AC off. Is that normal for an l300?

Any help on where I should look next is helpful.

Thanks.

[fdryer]

When you checked pressures and found it low, you fell into a false sense of satisfaction by assuming refilling will make cold air. You avoided what many aren't aware of or willing to acknowledge - a leak triggered by the pressure sensor enters fail safe mode by disabling compressor operation. When enough refrigerant is released, the pressure sensor detects the loss and sends a disable signal to the ecm. The ecm removes power to the compressor. Bypassing the compressor relay confirms loss of refrigerant. Buy and use a uv blacklight to find the source of the leak, make necessary repairs so the system holds pressure instead of leaking and your system will make cold air again.

Topping off is nothing but a band aid to refilling a leaking system. And resist temptations (if not already done) to use sealer; ackits.com has pictures of ruined systems completely contaminated from sealer use requiring a complete rebuild (an expensive mistake one member made here, admitted to it and hasn't replied since acknowledging the mess it created). Every factory installed a/c system never uses sealer for one reason - contamination. Refrigeration systems for cars use only three ingredients; r14a, oil and dye. If sealer was supposedly invisible and not harmful to any a/c system, ask yourself why doesn't every car manufacturer use it?

Unless you're willing to learn about refrigeration pressures and use a set of gauges, find the source of the leak with a uv light then determine what is required to repair it. Whether you know it or not, you just became an untrained a/c repair mechanic.

[pierrot]

The fact that the compressor was not previously engaging is part of the system's fail safe set up to prevent compressor damage when there is insufficient refrigerant in the system. While you were able to verify that the compressor was functional with the jumping of the two contact posts that was all that you really accomplished. Take a look at the pictures attached in post #5 from the post linked below and identify which one is in your car for us. The attachment at the left is the manual climate control head and the one at the right is the automatic climate control head.

http://www.saturnfans.com/forums/sho...limate+control

The air conditioning system shouldn't shut down merely because the blower is running at high speed. Nevertheless, based on other information you've provided I'm suspicious that,
1) you have a refrigerant leak somewhere in the system, and
2) perhaps there is a problem with the mode door which regulates the temperature of the HVAC system.
Item #2 is less likely over all, but not impossible to have occurred. I suspect that a leak is present because there was apparently no change in the air temperature coming out of the vents. (It would be a good thing to have an air conditioning thermometer to be able to verify HVAC air temperature as it helps to confirm the efficiency of the system.) Unless you have the necessary equipment to perform a refrigerant leak check then you'll need to take the vehicle to a professional who can diagnose your problem accurately.

[dbinteract]

Thank you for the information. I looked at the pictures.
I have the manual HVAC.

Yes, I suspected a leak too.. but the easiest place for me to start was making sure the compressor did in fact engage... so thats why I started there.
Next, I got a UV light and looked for a leak, but so far I cannot find anything. I did use the dye, but I cannot see anything. I did find a few spots that had oily residue built up, that that may be just from the age of the car. I tried to clean them off, and I will look for leaks again tonight.


I realize that topping it off is only a band aid, and again, I was doing it mostly to try and make sure the system was functioning. Which even though the compressor engaged, it is not functioning properly, as there was no cold air. Additionally, by getting the compressor to engage, I was able to discover the curious problem with the AC shutting off when the fan is on its highest speed.

thanks, any additional guidance is greatly appreciated.

[fdryer]

Examples of dye; both service valves will exhibit dye and glow with UV light illumination. If service valve caps aren't tightened, refrigerant can escape. Use the light everywhere, carefully tracing from discharge or suction side until you cover the entire plumbing above, below and sideways.

Refrigeration basics for your model, assuming a set of gauges are connected; Saturn pressures are monitored at 2k rpm (not idle). Normal low side (suction) will show between 25-35 psi, high side (discharge) will show between 125-250+ psi. You're now knee deep into refrigeration. Gauges are required for anyone seriously interested in repairing their system and willing to learn more than they know.

[pierrot]

^Our esteemed member, fdryer, is among a tiny number of members, as an L Series owner, who can provide truly cogent answers with regard to A/C work since he has/does perform his own repairs. Frankly, I admire that and I admire the fact that the OP is going through this on his own as well. As for me, air conditioning work is, perhaps apart from a simple r&r job like replacing an expansion valve, something I won't touch. (This is especially the case as it relates to warranties and warranty work - I like it when other people are responsible for it.) Once one gets into a full-fledged DIY repair with an A/C system then it includes an expenditure for various tools which are not often used.

If any one believes they're up to the challenge then, by all means, go ahead. Much care must be taken during this repair work as a potentially simple error could produce expensive (disastrous?) unintended consequences down the line. Air conditioning systems are not forgiving of such things.

[dbinteract]

Thank you,

Im going to look again for the leak. If I cannot find it, I will consult someone more qualified than me for sure. At least I know its not the compressor, and that is a good thing, if I do have to go to a shop, I will know right away if they are trustworthy, or worth their fees.