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Cb500fa fan not starting

305 Views 7 Replies 3 Participants Last post by  Trillian
Hello all,

It started all with when I attached my battery with wrong polarity after replacing air filter. When I realised problem I viewed the forum and replaced blowen fuse of 30amps. I'm an electric engineer and got to know how easy to attach wrong polarity in cb500fa.
After battery connection, I turned on the bike and just after riding around a km pgmfi mil indicator turn on, I restarted bike and it didn't come after that.
After that I noticed that my radiator fan is not turning on. Whenever we start the motorcycle, fan turns on for 2 to 3 secs but mine is not turning on. I checked basic diagnostics like:
Supplying 12v directly to fan, it turns on means fan is OK.
Swapping fuel pump relay with fan, still fan is not starting when switching on but fuel pump relay turn on means relay is OK.
Fuse seems OK but still swapped it with spare fuse. (I don't have multimeter as of today, will get it tomorrow), still fan is off while starting.

Is there any other diagnostics, I can do. What could be problem?

Sorry for bad English. 馃様
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I'm confused now. Do Fan starts for 2-3 secs when we switch on the motorcycle or it only starts whenever temperature is high and never ever?
It's CB500FA 2018.
Help is really appreciated.
Cooling fan only comes on with high temperature. Does the bike run ok when riding. Do you have a problem, or is it just the MIL light fault code you have a problem with. Did the MIL light come on when you were riding.
Yes bike is running normal. Today I rode around 21kms on my commute to work.
Yes mil light came when I was riding just after replacing my fuse. I was around 30kmph at that time when it came. It never came back again. I was thinking that fan also starts for a while when we switch on power.
Fan doesn't come on at all until water too hot.
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Yes. While waiting at fuel station I didnt turn the engine off and after some time it started.
Just because of my confusion, I wasted a complete day to diagnose a problem which was never there.
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Sounds like you are Human, we all do it.馃憤
As you probably realize now, the fan is temperature controlled and is part of keeping the engine at the right temperature. It needs this to meet its fuel economy and emission specs.
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