By david (208.130.246.157) on Wednesday, March 28, 2001 - 02:31 am:

i have a switch hooked up to my cooling fan. if i leave it off is the engine sopossed to overheat no matter what? i tryed leaving it off and driving it real hard for about 20 min., but it just stayed diectly in the middle of the temp gauge. could my temp gauge be faultly? i've seen it overheat before. how could i check?
i did do this test at night, too.

By Adrian (Civicguru) (203.42.97.227) on Wednesday, March 28, 2001 - 03:55 am:

You're quite unlikely to get your engine hot enough to need the fan running when actually driving it (a standardish engine anyway) and even if you do, the fan won't actually do a lot. The fan will only ever be effective when the car is stationary or travelling at very low speed. When moving there is air flowing through the radiator, when stationary there is not. If the fan is running all the time when moving it's just wasting power (it does take power to drive the fan).
If you hook a low wattage indicator light (say a LED) up to the fan to tell you when it's on you'll actually see it glow a little when driving at a decent speed (usually seems to happen at 100+ km/h). It's not the fan coming on, but the fan motor generating a small current (the air flowing through it spins the motor and it becomes a small generator) .

By ROotUS (203.20.149.5) on Friday, March 30, 2001 - 11:16 pm:

if you want to check for temp guage working or not... run engine without water - or DONT... your choice. but im sure that will show up on temp guage. otherwise run in your garage with the fan off and lights on (and air con if you got one).
or just trust it.
(but dont run without water - jokes)