Good day to all...I'm having a problem with my 1990 420 SEL I hope someone can help me with. My A/C quit working gragually over the last week. The fan is intermittant, even if you select defrost, which usually goes to full speed and hot when selected. It's not cooling, even though the compressor starts and runs when placed in A/C mode and there's no bubbles in the site glass. I DID however get the system recharged with "freeze 12" back in early spring and it seems to have been working fine. Is there some type of control unit for this system or maybe a logic circuit somewhere that could have gone bad? Thank you for taking the time to read this thread and any help you can offer!! Larry :-)