[gw84]

This is a little hard to understand. Are you saying that the left side fan doesn't run most of the time? Only time you've seen both fans running was when you were checking for codes? A while back I noticed that only the right fan on my car was running. We let the car run for several minutes trying to make it run warm, so that both fans would turn on. However it never came on. I don't think there is anything wrong here. I could be wrong, but if your second fan kicked on while you were working, then it seems to me like it is working. Did both fans just stop working???