This video shows how an normally-open cooling fan switch works. I also show how I tested my cooling fan switches. the switch turns on at 203 degrees Fahrenheit. The switches came off my Honda civic 93
Wow for the slightly lower level of quality of this video i wasnt expecting much but you did a fantastic job in demonstrating the science behind it pretty well and clear, I actually learned more then i expected, great job man!
Nice demo. My Honda has several switches like those, including an elusive one that makes the fan blow air across the engine block after the key is turned off but damaging heat still needs to dissipate.
Wow thanks for this well explained video now I understand why my radiator fan don't turn on automatically. My mechanic connects the fan direct but now I can fix this issue. Thanks again
Hello, great video but i have a little question. I am not good at multimeters :( Our EP90 starlet has a cooling fan that has never come on in months. Down to my basic electrical knowledge I decided to stick a piece of wire in the wire clamp that fits in the switch and rubbed the other end to the engine block and the fan went on. does this show that the switch is dead? (the switch has only got one terminal so i think the circuit is open when the bimetallic part is not touching the housing which in turn touches the engine block. when it gets hot it touches and closes the circuit) is this a good line of thinking?
Hey bro not sure if you're still around but thanks for this vid and info. I just got into cars recently and I've been learning a ton. Do you happen to know what this would look like if the thermoswitch has 3 prongs? My VW has 3(separate hi/low speed) and I've been trying to find info on how that would work compared to this usual 2 prong switch to no avail. Would it just have an extra bimetallic disc? Very interested in finding out. Hope you're doing well!
Fan was not working on the honda city 2008 I was driving. Fan turns on with the air-con on though, so there's that option to not overheat. Diagnosed the problem using your tutorials. Either the switch is bad or the thermostat (doubt it's the thermostat). I will pull out the switch later and test. Also will buy a replacement switch later. Thank you for your videos.
I found my switch was bad by disconnecting the fan connector and jumping the two leads with a paperclip my fans turned on which told me the fan switch was bad. the test in the video can be helpful however you could still have a faulty switch if it engages at too low or too high of a temp. the switch needs to engage at a specific temp just like your thermostat, a cars fan cooling too much can be just as bad as a fan not cooling enough.
thanks for posting this. im pretty sure this has gone bad on my 99 accord. my rad fans only come on when the AC fan is on. If i short out the fan switch with a paperclip, they come on properly.
Roy Johnson I would make sure the fans have a good connection by wiggling the wires ( car will be hot so be careful). I doubt that the switch is bad. For some reason there is no reply button by your comment. I hope this helps
no hablo ingles pero vi su vídeo...ayúdeme con algo ..tengo un instale un thermo switch y sube la temperatura ..me da continuidad con el multimetro ..pero no me activa el relay ..lo saco dejo los cables conectados ..le caliento con fuego igual me da continuidad pero ahí si activa el relay ..que puede ser ??
