I just had this problem on mine too... tried to fix it sunday but i dunno whats goin on but i do know a little... On honda engines there are two coolant temp sensors... one controls the fans and the other controls the gauge... I replaced the gauge sensor (this is located under the distributor and goes straight into the block (.75" bolt)) first (not knowing that it only controlled the gauge)and of course saw no results... but then I talked to a different guy at the parts store and there is another sensor that goes into the thermostat housing... it's shaped a bit differently and goes in behind the block where the lower radiator hose goes in... My fans now turn on but only when my gauge reads a little under halfway... this seems way too hot and my car never heats up this much and the gauge reads nothing when i'm driving... the air circulation brings the temp way down...