Based on the adice, I sent to air-con workshop to check why air-con is not cool at stationary. But cool air is present whenever the car is moving due to high rpm. Changed the expansion valve but it didn't help. Next, I was asked to change the compressor. (Probably weak). If it is not compressor then it must be the control board or sensor. Hey, I cannot just listen and pay whenever. Has someone out there experience the same problem. Should I just change the compressor?

Larrytay88,

been reading your posts, don't despair. I have similar problem with 95 940 in Florida where temps have been upper 90s for months. I keep a thermometer in dash vent, consistently reads 43-46 degrees Farenheit (after the AC has been on a few minutes). But, never totally comfortable in the car at low speeds or in traffic. Engine never overheats, temp gauge works, needle stays mid-range. My AC control unit went bad 2 years ago, installed new one from FCP Groton; AC worked again, but still experience problem at low speeds. On cooler days, or with partial cloud cover, outside temp falls to 80s, I have to lower AC fan to position two or one because it gets too cold. At night on the freeway, it gets so cold, I intermittently turn the AC off. But, like you, I have not isolated the root cause of the problem yet. I SUSPECT it has soemthing to do with a temp switch, temp sending unit, pressure switch, or some electrical or electro-mechanical device that doesn't work properly when the temp is over 85 or 90 degrees, likely due to insulation breakdown of the device. With 44 degrees at the vent, seriously doubt it is the compressor. Try placing a thermometer in your dash vent and get some insight into how system is operating.

BTW, read post from Jim Holst, a great poster, and in your case, he may be absolutely correct about the resoldering suggestion.



best of luck

I had two problems with my '93 940 AC. It wasn't getting very cold until I had made a fast run down the highway, then it stopped cooling totally.

I fixed the second problem by removing and resoldering the AC control board in the dash. The AC compressor clutch wasn't pulling in which led me to this repair. There are lots of references to this in the archives.

For the second repair, once the compressor was turning, I bought a r134 fill tool which had a pressure guage on a hose which connects to the low pressure side of the system at the accumulator on the firewall. This showed the low side pressure to be about 25 psi when the compressor was operating. It should be about 40 - 45 psi. The 'tool' has a place to connect a can of r134 and a trigger valve to let the r134 into the system. I let a little bit of r134 at a time into the system with the AC running and let the pressure stabilize. When the pressure with the compressor turning reached 40 psi, I quit. The AC now runs very cold.

I used a can of plain r134, no sealer, conditioner, or oil. I felt fairly certain that the AC system had just slowly leaked down since I've had the car a few years with no AC service needed.

The proper method of recharging is to evacuate all r134 then add the needed amount by weight.

There was also a factory TSB showing how to improve AC cooling at slow speeds by changing the electric fan circuit to make it run when at idle or slow speeds. I do not have this change in my 940.

I'm no AC expert but this is what got my AC working this summer.

Thank you for the advice. Please read my post on cooling fan temperature sensors. I'm thinking whether could it be due to the air-con temperature sensors located below the condenser especially my fan stop immediately when the engine is turned off. It should run for a minute or 2 until the cooling takes place!!!