Group:
’98 S90 has an A/C problem and I don’t know where to look.
Compressor cycles 5 sec ON and 5 sec. OFF after driving on a sunny 80 degree day.
Same while stopped afterward.
Electric fan behind radiator runs, as it should.
In-car fan runs and responds to the various settings.
However air is not coming out of the vents, in any of the positions on the dial.
Same on heat and A/C both.
If I hit a bump it can start blowing out the vents.
Hit another bump and it stops.
Today it started blowing while I was sitting at a light.
Later stopped when sitting at another light.
No effect from changing any of the A/C control setting.
Not real cold, so I may need Freon, but how is that related?


My big green Service Manual wiring book shows a device called: “Servo motor, mixing shutter”.
It seems to be buried in the dash area.
There is also a “ECC climate control module” that seems to be the box that all three adjustment knobs are mounted on.

Anyone got any suggestions as to where to start?
This is a late production US car so I expect it has the electronic control system.
Does the panel with the three controls come out by itself?
How to get the wood trim off without breaking it?

Thanks,
Rich

look at fan relay behind battery I had similar problems and luckaly new relay solved problem.

Chilliwack:
Thanks for the help.
However as I tried to explain, the fan runs normally in all speed settings.
The problem is that it does not blow warm or cold air out the vents.
But that is erratic as well.
Getting the trim off in one piece would allow me to look into the system.
How to do that?

Rich

The fan relay is not the interior fan but the fan for cooling engine without a proper working relay ac system will cycle but will not get cold,

Good luck

Your first problem, cycling on and off, sounds like it is low on freon.

The second problem sounds like one of the vacumn bellows being bad or possibly a vacumn hose under the hood leaking.

Jimo

Jimo:
Are you sure the 98" S90 still used vacuum operation? I don't think so.
I'm familiar with the earlier models and I could hear the system working.
However, I see no mention in the green book on wiring of any actuators for the bellows. It does have a unit called a flapper motor or similar. Electrically driven from the ECC control unit.

At this point, I would settle for knowing how to get the wood-grain plastic trim off. I can pry on the "attaching pins" or stubs if I know where they are. Otherwise I tend to break things.

Thanks,
Rich

Rich,

Maybe the 98 does not have the bellows, but a 96 does, so sorry that did not help.

I don't know how to remove the trim.

Jimo