Cadillac Owners Forum banner

96 SLS A/C problems

1140 Views 8 Replies 4 Participants Last post by  greg-sls
I got the message "Service A/C System A/C Compressor off" on the info display a while ago. I can't get it to come back. The manual says the sensors are bad. My heater still works but the A/C won't come on at all. Push the button, A/C OFF remains lit on the climate control display. Blower motor is still good. What happened?
1 - 9 of 9 Posts
Pull the DTC's. You are probably low on refrigerant.
As Ranger says...start with a can of freon and a basic fill tube connection. When you add the freon, it will be the port capped off with plastic cover nearest the accumulator (aluminum canister). First, clear all your ACM codes (read sticky on how to do that) and you have about a minute or so to add more freon when the compressor comes back online.
this is gonna be my weekend project. so if you dont mind let me make sure i got this right (we all know i'm not very good on this auto repair stuff yet).

clear my codes. then fill with coolant. now when you say i have a minuet to add it does that imply the car should be running with the a/c on when i fill?? or fill then top off when running?? i dont wanna screw this up.


also just to make sure i also have the right place to fill from. its literally right there left hand right when you open the trunk.

EDIT: also is there a kit any one would recommend?
Get the can of refrigerant (not coolant) hooked up. Purge the air out of the line that you connected to the car. Have someone start the car, A/C on max cooling and hold the RPM about 1500. Now open the valve to add the refrigerant. DO NOT use a can of refrigerant that has a sealant in it.
how do i purge the air out? and will the refrigerant come with a line and valve i need or do i buy this separate? sorry if i'm asking really dumb questions I'm really really not skilled at this stuff. but if you ever need any IT help just ask.
You need at very least a recharge kit that will have a can tap with a valve on it and a hose. You can buy the cans and charging kit separate or as a kit. Best is to have a set of A/C gauges (forget the ones that come on the can. They are useless. Connect the hose to the can and open the valve. Press on the valve inside the fitting on the other end. It should only take a brief push and you will get some very cold refrigerant shoot out. Now you have expelled any air in the line. Close the valve on the can and connect the end you just bleed to the low side service port.
awesome. i think i should be able to handle this. thanks dude!
To add to Ranger's suggestions, you should probably have a helper in the car. After you have cleared the ACM codes (do this with the Climate Control or "CC" off), have your helper bring up the revs to 1500. You are at the fill port connected with the freon (now bled of air) fill tube ready with the release valve. Have the helper turn on the CC (just touch the AUTO button). Now you have about a minute to recharge the refrigerant. If there isn't a serious leak, the "Low refrigerant" message should not re-appear.
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.