'93 940-- the car seems to run very smooth in town and on the highway until I turn on the AC. In town it's hard to tell the difference--AC seems to be working good(right about 50 degrees F at the vents in the driveway at idle) However---- when I'm at highway speeds,I feel what almost seems like the engine is intermittently missing--like it's being loaded. If cleaned the throttle body and the --what's that called-----the air bypass valve. Not being able to stick my head under the hood and drive down the highway, I can't tell if the compressor is cutting in and out. Oh --- the computer is clean-- no error codes on anything. One more thing--- when I first turn the AC on in the driveway with the hood open, I can see the compressor kick in and then about 10 sec. later the fan turns on and when the fan turns on, the engine stumbles and the rpm's drop just below 500. Is there a relay with bad solder joints somewhere ---I know my '88 240 had two different relays fail because of bad joints (fuel pump and overdrive) Thanks for any ideas!!