I know there are some common resolutions, so you need to understand the history first. 94 Saturn 4 dr / AT inherited the car from step daughter and thought youngest could fix'er up and have his first car. The boyfriend that ran it into the ground had jumped the engine cooling fan over to the A/C supposedly. I did find evidence of wire splicing and the like from the cooling fan. PROB: - A/C compressor clutch won't engage (will engage if jumped) when A/C button turned on. - Cooling fan won't come on even past 3/4 on temp gauge (will come on if jumped) HAVE TRIED: - Replaced the coolant temp sensor with one of the all brass ones - Verified that both A/C and Fan relays are good - Jumped the A/C unit and verified that the clutch does engage - Verified continuity from compressor back to relay - Replaced the PCM - Replaced the A/C board behind the controls (could see hot spots in 2 places and the circuit was broken) Light now comes on when A/C pushed, but clutch doesn't engage. - Verified that cooling fan does work when jumped. I know these can be somewhat related anyhow, but I'm afraid this "mechanic" boyfriend of hers really screwed some stuff up here. At this point, all I can guess is that there is a wire problem between the relay/fuse block and the A/C board behind the controls. I did notice that this particular year had another black wire spliced in (from factory - verified by comparing to others in junk yard) to the green wire going to compressor. I'm guessing that this is so that when A/C is on, PCM or Cooling fan relay ensures that cooling fan is on. Please pass on any ideas or experiences. We've got it running great except for the overheating and A/C issue.