MVS Forums member edelmatt asks how to approach getting his 240 DL’s air conditioning to function again… including if it isn’t easier to switch wholesale to the more modern R134a AC system. From his post in the Volvo 240 forum:
Working down the list of ills for my 1990 240, the AC is up next. It appears to be the original R12 system. I gather this by the fact that there is still the ‘factory fill’ fitting downstream of the drier.
Unfortunately I can not find any specific diagnostic guide for this year of 240. I don’t even know where I would connect a manifold diagnostic gauge. Would the service ports be around the receiver/drier, compressor, or condenser? If the receiver/drier, do I then need to remove all the interior panels to reach the service ports? The most likely seems to be that both high/low ports are on the compressor and a PITA to get to.
edelmatt »
There is refrigerant in the system. Verified. Pressures unknown. Waiting to run into my AC neighbor to see if he can help get a reading and possibly recharge for me. The only piece I can really look at right now is why the switch/knob only seems to engage the compressor clutch sometimes. I don’t know the functionality of that control. But I surmise that it is both a sensor and a switch. If I can simulate “on” by just shorting two of the leads then that would make the rest of the process easier. If I can’t keep the compressor running it’ll be tough to finish the job.
93regina you’ve been pretty helpful so far. What do you know about that switch?
I think the two green wires are for the thermostat switch, and the knob varies the response of the thermostat. When the thermostat warms past the threshold set by the knob, it will short the two greens together and send power to the switch on the receiver/drier. Only then will the compressor turn on. I’ll wait and see if anyone disagrees, but my thought would be to wire in a rocker switch to the green wires and take the switch/thermostat out of the mix.
Last Updated on August 19, 2020
