climate control malfunctioning?

Post by **318mike** » 15 Sep 2012, 18:24

I have a 94 960 with what seems to me to have a climate control problem.The symptoms are, no control over vent direction,the ac compressor stays on no matter what I do and the radiator fan stays on all the time that the car is running.I can hear the blower change speeds from 1 to 5 but almost no air comes from the vents.The little bit of air that does come from the vents is luke warm no matter what I do...any thoughts....thanks in advance

Post by **Fish stick88** » 15 Sep 2012, 18:28

First off, Do you have manual or electric climate control? When did this all start? What is your ambient temp sensor saying? Any codes if it is ECC?

Post by **318mike** » 15 Sep 2012, 18:51

I just bought the car recently with the problem that i described.What is the difference between ecc and manual.Sorry if this a stupid question.

Post by **Fish stick88** » 15 Sep 2012, 18:58

No such thing as stupid questions. The difference is the way it works, by manual climate control (what i have) by turning the knobs you are pulling cables hooked to a series of flaps, with Electronic, it is all activated based on position sensors inside the cabin, such as the flaps opening and closing automatically based on your temp setting compared to interior current temp.

In Conclusion.
If your drivers side, and passenger side have little tiny bars from hot to cold you have manual.
If they are labeled with temperatures, you have electronic.

lindy8_man · Post by **lindy8_man** » 15 Sep 2012, 19:46

Or it could be vacuume controlled. The s90's and 960's have a lot of posts about failing vacuume servos. There are three to four under the dash. You may or may not hear a hissing noise. They can have all kinds of venting issues. The AC running all the time is a mystery. I suppose if air is not allowed to pass the AC coil, it could freeze up, and force the compressor to run and run... Or you could just be low on coolent... But usually when that happens the ac cycles on and off with about 5-8 seconds in between. Sooo. More info please... and do a search for leaking vacuume servos (solenoids / motors).

Post by **318mike** » 16 Sep 2012, 05:27

I have electronic climate control.Thanks fishstick for explaining the difference.I should clarify that the compressor cycles every few seconds but the coolant fan never shutsoff ,its as if the ac remains on even though the switch is turned off and the temp on the dial is set for 80+.With all of this happening there is still nothing coming from the vents neither hot or cold air.The only thing that I have control over is fan speed.I can hear the motor go up and down as I turn the dial from 1 to 5.I looked under the dash and I see what looks like three hollow balls (vacuum balls?... feel free to laugh),coolant level is fine.I am thoroughly confused,but I really appreciate the help.

Post by **Fish stick88** » 18 Sep 2012, 08:30

Since I do not have the electronic system I'm afraid I won't be of much help from here out. Sorry. The balls you're refering too sounds like something on electronic units, I don't have them on mine.

lindy8_man · Post by **lindy8_man** » 22 Sep 2012, 01:32

So for your "electric" system, I think you have an electric/vacuume hybrid like my s90. My chilton manual seems to indicate that... and the black plastic "three hollow balls" I believe is a vacuume reservoir. take a look directly above your accelerator pedal. There should be black round piece that looks like a car horn (best way for me to describe it). This is a vacuume servo/bellows/motor. The controls are electronic that controlls the vacuume module that controls the bellows that opens and closes your vents.

I had a problem back a few years ago. do a search for "S90 with a vacuum leak under the dash"

My 98 s90 had 3 Vacuum servos under the dash. I could hear a slight hissing when the car was running. When I would accelerate or just push down the pedal, the hissing would stop, and the vents would switch to defrost. I also lost cruise control. These cars have a lot of vacuum controls. The bellows next to the gas pedal is the easiest to get to and replace. You can hope this is the one that has gone bad. with the car running, see if you can hear a hissing, or if you can see a tear. the diaphragm is flexible.

The remaining two servos are in "the briefcase." This is the air handler box behind the center of the dash. The bad news is that it is probably the most expensive job you can have done labor wise. I think my job with replacing the bellows and my heater core landed around $1200. You can pull the dash and DIY... I couldn't find all the screws. But others have said no problem...

There are some alternatives:
viewtopic.php?f=2&t=7094
viewtopic.php?f=2&t=21460&p=93706&hilit=vacuum+easy#p93706
viewtopic.php?f=2&t=4210&p=14040&hilit=vacuum+easy#p14040

I don't think your cooling fan staying on all the time is connected to your climate control problem. I would check on your coolent temp sensor (it is in the radiator on my s90). The wiring diagram for the 94 960 shows a low speed pressure switch connected to a cooling fan relay with a BL/B wire. and a red and green wire going from the relay to the fan motor. Since your fan is stuck on, first check the sensor, then the relay (in the relay box there should be a diagram in the lid), then hunt for that "low speed pressure switch."

lindy8_man · Post by **lindy8_man** » 22 Sep 2012, 21:23

While poking around my car today, I found that the relay for the fan motor is directly under the passenger side access panel of the headlight... Not in the relay box.

Post by **318mike** » 30 Sep 2012, 07:31

I was searching for vacuum leaks and while under the hood I found a vacuum line just lying there unattached.One end of it goes into the fire wall just above(what i will call the freon tank)and there is another vacuum line just about an an inch or so above it coming out of the firewall going into a valve that is on what looks like the heater core hose.I can't seem to find where to attach that vacuum line.Also I still can't turn off the ac compressor it cycles every 10 seconds or so,the ambient temp is 52 degrees the control is set for 80 and the ac button is off.