I had a check engine light come on tonight on my 99 s70 base. It has 60 miles to the 130k mark. I pulled over at a gas station and checked the engine. There seemed to be a hissing sound between the overflow coolant tank and the timing belts near the middle to the front of the engine bay. After wiggling some hoses I restarted the car 3 times and each time the check engine light kept coming on immediately. I then opened up the main "important" fuse compartment near the driver side mid engine. I popped out the big modules and replugged them back in once I could see nothing obviously wrong. Then I checked the four 15 and one 20 amp fuses, they were fine. I then did a visual inspection of the other larger fuses and the metal was still attached. I then closed up shop and restarted the car. The light did not come on.

Did I fix the problem or just mask it?
What could this be caused by?
If I went to AutoZone to have the code read, would the code still show up even though the light is still not on?


A little background info:

1. Had heater core replaced, and a refill of freon. Since then constantly getting low coolant light on after a couple of seconds once started. The coolant is topped off and hasn't lost any for over a month.
2. I have a bad compressor clutch on my a/c compressor. The compressor is not bad, only the clutch. When it gets hot the windings of the clutch loosen up and the compressor is disengaged. I am waiting for a backordered clutch assembly since it is less than a compressor and clutch. For $150 more I can get a new compressor too.

How much time do I have on my compressor and should I go ahead and spring for the new compressor also?