ran the engine at a fast idle today for AGES, but the fan never came on. I got paranoid in the end and decided to test the radiator fan switch out of the rad. Question is, how?! its a polo radiator, using the standard fan switch. If i stick it in a pan of boiling water, what should happen?!

ps i know the fan itself works cos i shorted it, and it came on well.

I was considering doing this myself before I start the engine for the first time and inadvertantly melt it!

My best guess is that once the switch reaches a certain temp (82C?) it will switch and allow current to flow. Therefore if you put a multimeter across the terminals you should get a circuit at anything above 82C. You could use a thermometer or something to get an idea of how hot the water is. Maybe start off with a pan of boiling water (there should be a circuit here!) and wait for it to cool. As it passes 82C the switch should flick again so that no current passes

Pete

It takes forever for the fan to cut in.




i]Originally posted by JoelP
ran the engine at a fast idle today for AGES, but the fan never came on. I got paranoid in the end and decided to test the radiator fan switch out of the rad. Question is, how?! its a polo radiator, using the standard fan switch. If i stick it in a pan of boiling water, what should happen?!

ps i know the fan itself works cos i shorted it, and it came on well.

It needs to be pretty hot for a rad fan to kick in, 97c come to mind for some models.

The switch itself may have 2 temperatures stamped on it. (I just changed one on a golf and that had iton the face that is inside the rad) The higher temperature was the temp at which it will switch on and the lower the temp it will switch off at as it cool down.

cheers fellaz, i'll rig something up this afternoon and test it.

It takes mine a very long time to get to heat with the bonnet off, if your able fit the bonnet and see if that helps. If heat can escape from the exhaust,block and coolent pipes easy then the engine may well never hot enough to switch the fan, my fan comes on at 99 degC

My fan is on a switch, not thermostatic, and I have never actually had to use it even in hot weather, but I do switch it on occasionally to see if it still works.

tell it you love it, and that its the most gorgeous thing youve seen, that you love its boots and cant wait to get inside it.


That might make it hot


dont work for me tho

atb

steve

lol! i know the engines thermostat works anyway, cos the rad pipes got hot. So all is good. Soon as i get a small altenator im on the road!!!!