2000 C230 A/C not working
08-13-2016, 07:20 PM
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2000 C230
2000 C230 A/C not working
The compressor clutch engages when A/C is on. Blows 15 degrees above ambient outside air temp. The AC worked great one day, then intermittently worked cycling on its own between 130 deg F hot for 10 minutes and 45 deg F cold for 10min, and after a week of this, now only hot.
I did a rudimentary check the duo valves. The solenoids click when power applied or removed via their electrical harness. With the air on, I turned the temperature dial to "hot" and inside air temp rose to 160deg. With the air still on, I turned the temp dial down to low, and the blowing air is 130deg. I squeezed the incoming duo valve hose to prevent coolant flow through the duo valves, and the inside blowing air temp dropped another 10 degrees, which makes me think the duo valve may be held open inappropriately. Not sure if they're bad, or if some electronics are holding them open. I could test with multimeter, but not sure what appropriate values should be.
I replaced the evap temp sensor, but no effect. (I had no evidence it was bad, except that it the symptoms of a bad evap sensor are apparently similar to my symptoms -- that and it was cheap and easily accessible.)
I have no AC electronic diagnostics info, because I have the analog/manual dial AC control unit. No OBDII codes present.
If anyone has any suggestions or comments, I would be grateful. I'm a bit lost. Thanks!
Update 1: Still no luck, but I did take apart the duo valve, just to be sure it wasn't gunked up, but it was fine. I did notice the aux (condenser) fans never came on while parked for a long while with the engine & ac on, even though the compressor clutch was engaged -- although I don't know if that's normal or not. I thought that might be an issue, but, I discovered by accident I could get the aux fans on by removing an 10 amp A/C fuse and they roared to life. Had no affect on cooling.
Update 2: The temperatures of both AC lines going into and coming out of the compressor are both hot, which someone elsewhere suggested meant that the refrigerant wasn't flowing for some reason. Which, I guess is weird, because the compressor engages.
I did a rudimentary check the duo valves. The solenoids click when power applied or removed via their electrical harness. With the air on, I turned the temperature dial to "hot" and inside air temp rose to 160deg. With the air still on, I turned the temp dial down to low, and the blowing air is 130deg. I squeezed the incoming duo valve hose to prevent coolant flow through the duo valves, and the inside blowing air temp dropped another 10 degrees, which makes me think the duo valve may be held open inappropriately. Not sure if they're bad, or if some electronics are holding them open. I could test with multimeter, but not sure what appropriate values should be.
I replaced the evap temp sensor, but no effect. (I had no evidence it was bad, except that it the symptoms of a bad evap sensor are apparently similar to my symptoms -- that and it was cheap and easily accessible.)
I have no AC electronic diagnostics info, because I have the analog/manual dial AC control unit. No OBDII codes present.
If anyone has any suggestions or comments, I would be grateful. I'm a bit lost. Thanks!
Update 1: Still no luck, but I did take apart the duo valve, just to be sure it wasn't gunked up, but it was fine. I did notice the aux (condenser) fans never came on while parked for a long while with the engine & ac on, even though the compressor clutch was engaged -- although I don't know if that's normal or not. I thought that might be an issue, but, I discovered by accident I could get the aux fans on by removing an 10 amp A/C fuse and they roared to life. Had no affect on cooling.
Update 2: The temperatures of both AC lines going into and coming out of the compressor are both hot, which someone elsewhere suggested meant that the refrigerant wasn't flowing for some reason. Which, I guess is weird, because the compressor engages.
Last edited by sejmann; 08-14-2016 at 06:32 AM. Reason: added info
