I've been meaning to get around to this for a while.

I know it's an old thread but I wanted to thank Mr. Civic2Scooby for the great pic and advice in this thread that led me to solve my fan problem last month.

For those who may have a similar issue - my car never overheated, even sitting in a drive thru last month for 10 minutes after drving several miles in 80 degree heat, not only did my fan not come on once but the temp guage never read over half way(it's normally just below 1/2). In fact, when I left the drive thru I noticed for the first 30 seconds that the car didn't feel normal, like a lack of power This was the occasion that convinced me something was wrong.

I don't want to go into the long, boring specifics but the guage does in fact work correctly to the best of my knowledge.

Last year, also during the summer, my fan would come on sometimes but it took a very long time, I just thought it was normal for 5th gens civics or that running ethanol might have to do with it.
Now with the new thermoswitch (not a spoon, regular from Beck/Arnley) it comes on 2 or 3 times on the rare drive-thru visit. That's even in 70 and below weather.

Obviously the thermoswitch wasn't working correctly for a long time and the ECU was compensating by retarding the ignition and running rich, I just had no idea.

Anyway, for posterity, here's an attachment photo that Civic2Scooby posted in another thread.