: '98 Seville No Air Conditioning!



98_SevilleSTS
07-10-11, 10:45 PM
Hi, my Seville air conditioning stopped working. I charged it a month ago, and it has been ice cold. Then yesterday, just vent temperature air, even on defrost. Tried disconnecting the battery, etc. I do not think that the compressor is kicking on, but am not positive. I hooked up a pressure gauge, and it shows low side pressure of around 40, but if the compressor is not on I'm not sure that is a valid reading. A/C fuses are OK. These codes are new (and current): P1520, U1255. Could they be related to this? Also, I seem to have lost the ability to enter into "Feature Programming" mode, and maybe other things, too, since as I understand the U1255, it is saying that there is a lack of communication between modules.

Prior to this A/C issue, the fuel release door relay was opening the door every 70 seconds. I pulled a few fuses, but believe that I put everything That fuel door opening has stopped, but so has the A/C! The electrical system on this car drives me crazy. Any thoughts are greatly appreciated. Thanks.

Wendy-J
07-15-11, 10:38 PM
Module communication issues might be caused by a faulty connection to the module. Locate your blower control module and see if the contacts are clean or dirty. If dirty, clean them with a pencil eraser or a very small fine bladed flat blade screw driver. That MIGHT do it. Then again, I might be blowing smoke out my ar$e.

Wendy

98_SevilleSTS
07-16-11, 10:53 PM
Here is some more info: I was incorrect about the compressor, it *is* coming on. I continue to get some strange codes, but perhaps they are unrelated to the A/C not working? My understanding is that the cooling fans are supposed to run on low whenever the A/C is turned on, and they are not coming on at all with the A/C on max. I swapped all 3 of the cooling fan relays but that did not make a difference. If anyone has any other ideas, please chime in!

Wendy-J
07-17-11, 12:07 PM
Well, my '93 only has the fans kicking in when the engine and coolant temps get high enough. However, that might not be the case five years later, so I'll steer clear of that one.

If the compressor is kicking in, one could assume the charge is still good if you've had the engine speed up over fifteen hundred or so, so that would rule out a leak to the atmosphere.

I think I'd try clearing the engine codes from the climate control centre first.

Then, I'd bring the engine speed up to about two thousand to twenty-five hundred RPM to ensure good high and low pressures in the system. Mine has an interesting gremlin. After being evacuated and recharged, you need to clear any codes, then bring the engine speed up in that range before the A/C kicks in. Then I might as well be in an ice box, it gets so cold. I still haven't figured that one out, but it worked.

As for what your codes are, there are several stickies, as well as sites on the web with excellent descriptions. I printed out the instructions from this site, but for my car, not yours : http://myweb.accessus.net/~090/dtcobd2.html

There are even procedures for clearing the codes from inside the car and not under the hood.

Wish you luck,
Wendy

98_SevilleSTS
07-19-11, 11:57 AM
Thanks for your input. The service manual is cryptic about the fans, but I think you are right--they must not automatically come on with the A/C the way many cars do.

I'll try bringing up the RPMs and see if that works for some reason. Otherwise, I think I'll have someone look at it on Thursday. Will post the result here if it is anything that could be of value.

Ranger
07-19-11, 09:22 PM
Wrong. The fans DO (or at least are supposed to) run at low speed anytime the A/C is on below 40 MPH. Try spraying the condenser with water while the A/C is on and see if that brings back cool air to the vents. If so, the fans are your problem.

P.S.
You need to check both high AND low side pressures.

Wendy-J
07-20-11, 10:37 AM
Ranger,
Perhaps I never noticed, because I usually wind up with a normal operating temperature engine compartment before I wind up needing to open the hood. My A/C has performed flawlessly since bringing it up to speed that one time. It doesn't matter how slow, how fast or how cold the car is since then. Turn it on and the A/C works.

What you say makes sense. The thing is, it should be that you aren't getting sufficient cooling of the refrigerant. I'd expect SOME cooling -- the kind you get with an insufficient charge, a drop in vent temps. but not sufficient drop to do any good. However, it IS a STRONG possibility. I just never experienced one that made NO difference at all. I have had cars that needed to have the condenser cleaned from the outside before the A/C worked properly, but it did work to some extent, just not well. *scratches head*

With a blocked condenser, you'd have to clean it. However, we're talking really really blocked, not just a few bugs. See the Love-Bug threads in detailing if you want to get your skin crawling. Running a hose from the engine side, through the radiator, to and through the condenser to the front bumper usually gets a good bit of road gunk out, although it can take a bit of time for bug gunk to soften before they flow out. Again, see the love-bug threads for some really icky pics.

In preparation for long cross country trips, I used to string the soft nylon screening you find used for modern tent windows behind the grill but in front of the condenser. It caught the bugs and other road debris before impact with the condenser. If this is an issue -- as it may well be -- that will be a possible solution AFTER the airflow has been restored. Thanks for the minder and for keeping me straight.

Wendy

Ranger
07-21-11, 10:55 AM
I have used those radiator screens religiously until I discovered that they deflect more air than they pass many years ago. I had an overheating problem at highway speeds. Removed the screen and the problem went away. Haven't used one since. Your results may differ.

98_SevilleSTS
07-21-11, 04:31 PM
Turns out that the system was basically out of freon--again (just charged it 5 weeks ago). Not sure why the compressor was running at all. Also not sure why there wasn't a period of reduced cooling efficiency, meaning, it went from ice cold A/C to no A/C the next day. The codes and other electrical issues are apparently unrelated to this issue. The mechanic dye tested it today, but cannot find a leak. We are both concluding the leak must me at the evaporator core. Bummer! Thanks to all for taking the time to reply.

Ranger
07-21-11, 09:37 PM
it went from ice cold A/C to no A/C the next day
That would indicate a rather large and sudden leak.