2005 Taurus - 6cyl - 3L - 85K. 2nd post on this on. Have had this vehicle to 2 mechanics now and problem is still there. First mechanic checked the refrigerant pressures, added dye, couldn’t find a leak. Told me that he had to add a small amount of R134 and the pressures were “spot on” but the problem was still happenning so he supposedly trouble-shot the system and found it to be electrical. He said that the controls on the dash were causing the problem and changed them. When I picked it up, everything worked fine for the first day. After that, the same thing happenned where it would intermittently work. I took it back to another mechanic (who specializes in AC work) and he evacuated and recharged the system (also said that he added dye and couldn’t find any leaks). When I questioned this, he said the pressures were low and that would cause the intermittent loss of the AC cooling. This time, it work for 2 days and then the same thing happened where it intermittently works. There is no pattern at all to it working. Sometimes it’s when the car is first started ; sometimes it quits just driving down the highway ; and sometimes it quits for 5 minutes and then just comes back blowing ice cold air. I suggested the AC compressor clutch or coil to the 2nd mechanic and I’m not sure he even checked it. Does this “still” sound like a leak somewhere or more electrical ?
Personally I think it sounds more like an electrical issue. I’d start by checking the wiring and connector going to the a/c compressor maybe even cleaning the connector with electrical parts cleaner to be sure you have a good/clean connection. I don’t know whether they still used a CCRM (constant control relay module) in the '05 Taurus or not like they did during part of the '90’s, but if they did it houses the a/c relay and a common problem with them was the solder joint breaking lose allowing it to sometimes make a connection and sometimes not causing an intermittent failure. If you find your car does have a CCRM it is a sealed box containing several relays. You can remove the CCRM, drill out the rivets in each corner and lift the top off the CCRM, the a/c relay was the smallest relay in the CCRM during the '90’s and if it’s got a broken solder joint it will probably be burnt around the lose connection, clean the protective film off the circuit board, take a soldering iron and re solder the connection and put the CCRM back together using small nuts and bolts. I repaired many of them this way and is much better than the approximately $300. price tag of a new CCRM. If it ever completely stops working the relay has probably gone out, in that case you just need to find a replacement relay desolder the connections and solder in a new relay. If your car doesn’t have a CCRM it will have an a/c relay somewhere and it could be a bad relay or connection going to the relay. Good luck.
The compressor clutch coil may be failing intermittently after it heats up.