Author Topic: cooling/fan questions  (Read 683 times)

Offline sport rider

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cooling/fan questions
« on: June 20, 2019, 05:34:09 pm »
fan not coming on.  the radiator I have it from a known working bike.  I'm not yet at a point of identifying the sensor as the problem.

but....

looking at the wiring diagram, it shows  a yellow/white wire from the "Coolant Temperature Sensor".  it also shows a "coolant fan switch" with red/white and blue/white wires.    that's the color of the wires going into the temp sensor (what I'm calling it) on the side of the radiator.

two questions to start.  what/where is the yellow/white coolant temperature sensor.  also, where is the in-line fuse which connects to the red/white wire in the diagram?

in case you need reference, I've got snippets of the two components on the diagram.

Offline MAN OF BLUES

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Re: cooling/fan questions
« Reply #1 on: June 20, 2019, 05:46:56 pm »
temp sensor plays no part in fan operation, the sensor is located on the back of the thermostat housing, a small fitting, with a wire fed thru a "faston blade connection"; it only effects the actual gauge reading.

The actual fan switch, is the one on the left bottom side of the radiator, this controls the "on/Off cycle" of the fan, and is dictated by it's own temperature controlled switching within that device.

The fuse, is the single one, in a single White plastic "fuse holder" adjacent/attached to the J box, It also controls the clock features on early models. some changes within the lighting, and J box changed in '94 but basically everything else remained the same.

easy check of the actual fan and power, is to wrap a paper clip around thee 2 pins (with wires still attached)on that fan switch, shorting them together, the fan should run regardless of temperature when the bike is on.

30 YEARS OF KAW.....

Offline sport rider

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Re: cooling/fan questions
« Reply #2 on: June 20, 2019, 06:07:49 pm »
Thanks Rich.  it's not the fuse.  even though I had not located it, a quick check with the volt meter showed I have power on the red/white.

will go find a paper clip now!  :)

Offline sport rider

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Re: cooling/fan questions
« Reply #3 on: June 20, 2019, 06:51:32 pm »
have I mentioned how much I despise electrical problems?   :-[

made a jumper cable to plug the red/white and blue/white wires together.  volt meter reading at the red-white wire is 11.  fan did not come on.  pulled the plug.  the plug reads 10.9.  I started the bike and readings were the same.

I have a spare fan, so plugged it in to see if it worked.  no dice.  either I have two bad fans or perhaps the plug is corroded and neither fan is making good contact?  I'm going to hit the connections with baking soda and vinegar to see if that helps.

I'm also going to work on wiring the fan directly up to a battery and double check both of them.

any other thoughts/ideas?

Offline kzz1king

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Re: cooling/fan questions
« Reply #4 on: June 20, 2019, 07:00:54 pm »
First thing I would do is as you sugested, wire to bat to check function. I was always going to just wire a switch in mine but never did.
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Offline sport rider

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Re: cooling/fan questions
« Reply #5 on: June 21, 2019, 01:42:49 pm »
fan on the bike and spare fan both work jumped to the battery.  still nothing when I plug it into the harness with the jump across the switch.  cleaning harness connections now.  we'll see if that gets it going.

Offline sport rider

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Re: cooling/fan questions
« Reply #6 on: June 21, 2019, 04:44:39 pm »
well, I'm scratching my head now.  jumping to both fans turned them on.  cleaned both ends of connectors but can't get any power to the fan.  next step is to replace the connections.  hate to do that, but not sure there's any other option.   :(

Offline MAN OF BLUES

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Re: cooling/fan questions
« Reply #7 on: June 21, 2019, 07:22:39 pm »
I... cannot or understand this whole thing.
fans, 2 wires, joined, run to the swithc.
2 wires run to the power source.
power source is fused.


I'm done.
good night. sorry, but I am not there to say "DOH.. what were you doing".


it's a simple circuit.  and I am at a loss, to guess any further.

30 YEARS OF KAW.....

Offline connie_rider

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Re: cooling/fan questions
« Reply #8 on: June 22, 2019, 09:25:27 am »
Sport Rider, I'm not an electrical guy either.
I just realized that the plug {you may be referring to?} is the plug at the fan?
If yes, that is probably not the problem. Problem is probably at the thermostat/switch.

#1} Check voltage on both sides of the fuse to eliminate that as a problem.
#2 Assuming you have voltage at both ends of the fuse, the problem is probably the thermostatic switch.
          That thermostat/switch is located on left/rear side of the radiator.
           I think it has 2 wires plugged into it.?
           If yes, disconnect them from the thermostat and short them together.
            Fan should run.
#3 If no run, check voltage at those wires and report back...

NOTE: The fan is battery powered, {not switched power} and shorting them together will make them run regardless of the switch being turned on.

Ride safe, Ted

PS: Your voltage seems very low.

Offline sport rider

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Re: cooling/fan questions
« Reply #9 on: June 22, 2019, 09:26:39 am »
Thanks for sharing in my frustration Rich.  I pulled the factory clips off the wires and hard wired everything.  still doesn't work.  the only thing I can conclude is the wiring harness has a problem somewhere.

I swapped the battery back into my parts bike and connected the spare fan to it.  then jumped over the temp switch and fan took off. 

I walked away for now.  lots of wild ideas running through my head.  swap wiring harness.  swap start over with the parts bike as the basis. 

 :'( :'( :'( :'( :'( :'( :'( :'( :'(

I'm going out on the lake tomorrow and drink beer.

Offline sport rider

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Re: cooling/fan questions
« Reply #10 on: June 22, 2019, 09:38:27 am »
Sport Rider, I'm not an electrical guy either.
I just realized that the plug {you may be referring to?} is the plug at the fan?
If yes, that is probably not the problem. Problem is probably at the thermostat/switch.

#1} Check voltage on both sides of the fuse to eliminate that as a problem.
#2 Assuming you have voltage at both ends of the fuse, the problem is probably the thermostatic switch.
          That thermostat/switch is located on left/rear side of the radiator.
           I think it has 2 wires plugged into it.?
           If yes, disconnect them from the thermostat and short them together.
            Fan should run.
#3 If no run, check voltage at those wires and report back...

NOTE: The fan is battery powered, {not switched power} and shorting them together will make them run regardless of the switch being turned on.

Ride safe, Ted

what I did was make a small jumper wire with bullet plugs which match the wires into the thermostat/fan sensor.  testing voltage at both ends of that jumper after installing, I got a reading of 11.9.   I tested the plug where the fan wire connects to the wiring harness which is up under the neck of the bike.  testing the voltage there was a reading of 11.9.  but when I plugged the fan into it, nothing.  same results for the fan on the bike and my extra fan.

since there was no battery in the parts bike, I swapped the battery over from the project bike.  I plugged in my jumper wire across the thermostat/fan sensor.  plugged in the spare fan to the harness connection and it works.

in testing both of the fans, I also made a test wire set.  basically mini jumper cables.  I used nails on the end of the wires for probes.  the other end of the jumper connected to the battery.  when I used this to test the fan on the bike and the spare fan, both work.

as Rich said, it's a simple circuit.  my only guess is that something in the harness is bad?  maybe something is pulling power away?  maybe the ground is screwed up?  the ground wire is the only oddity of the circuit.  red/white wire into the sensor.  blue/white wire out of the sensor.  same blue/white wire at the fan plug which gets joined by a black/yellow wire which is a common ground.

I tested the power at that plug connecting to the two wires in the plug and got a good reading.  I also took a reading with the blue/white power and grounded to the frame.  good reading.  plug the fan in...nada.  :(

Offline Nosmo

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Re: cooling/fan questions
« Reply #11 on: June 22, 2019, 12:25:21 pm »
have I mentioned how much I despise electrical problems?   :-[

made a jumper cable to plug the red/white and blue/white wires together.  volt meter reading at the red-white wire is 11.  fan did not come on.  pulled the plug.  the plug reads 10.9.  I started the bike and readings were the same.

I have a spare fan, so plugged it in to see if it worked.  no dice.  either I have two bad fans or perhaps the plug is corroded and neither fan is making good contact?  I'm going to hit the connections with baking soda and vinegar to see if that helps.

I'm also going to work on wiring the fan directly up to a battery and double check both of them.



any other thoughts/ideas?

It won't.  Common mis-conception.  Baking soda is alkaline and vinegar is acidic, they neutralize each other.  The foaming action is impressive, but it ends there.  Read last paragraph in this article. 

https://abc13.com/health/household-chemicals-you-should-never-mix/1748504/

To sort of restate what others have said, this is how I would troubleshoot it:

Check for voltage between the black/yellow ground wire and the red/white wire coming out of the fuse.  Should be battery voltage.  If YES, jumper the red/white and blue/white wires at the cooling fan switch, to eliminate that switch.  Fan should run.  If NOT, pull the fuse and check for corrosion on its blades and socket.  Try replacing the fuse, (they can go bad internally) see if that fixes it.  If NOT, then you have a problem with those wires or connectors, corrosion or looseness.  Check this by jumpering from the white wire going into the fuse to the solid blue wire going into the fan motor.  This by-passes everything.  Fan should run.  If it does, then there is a problem with wires or connectors or cooling fan switch. You say you've jumpered that switch so next suspects are wires/connectors.  Don’t be fooled by having “good voltage”.  A circuit can have “good voltage” when not under a load (meaning not drawing any amperage), but not be able to carry any current and make the appliance run.  Your voltmeter draws only a few milliamps.  If there is a bad problem with the wires, just run some new ones.
« Last Edit: June 22, 2019, 01:04:01 pm by Nosmo »
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Offline connie_rider

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Re: cooling/fan questions
« Reply #12 on: June 22, 2019, 12:59:52 pm »
You have voltage/current loss somewhere..
What is the voltage "at" the fan on the project bike?

Just had a thought  :nuts:;   Is this fan installed on the Project/Café bike??
If yes, the head pipes of the header I gave you, are VERY close to the fan.
Is it possible the head pipes are keeping the fan from rotating?  :doh:

Ride safe, Ted
« Last Edit: June 22, 2019, 04:03:39 pm by connie_rider »

Offline sport rider

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Re: cooling/fan questions
« Reply #13 on: June 22, 2019, 03:14:25 pm »
It won't.  Common mis-conception.  Baking soda is alkaline and vinegar is acidic, they neutralize each other.  The foaming action is impressive, but it ends there.  Read last paragraph in this article. 

https://abc13.com/health/household-chemicals-you-should-never-mix/1748504/

To sort of restate what others have said, this is how I would troubleshoot it:

Check for voltage between the black/yellow ground wire and the red/white wire coming out of the fuse.  Should be battery voltage.  If YES, jumper the red/white and blue/white wires at the cooling fan switch, to eliminate that switch.  Fan should run.  If NOT, pull the fuse and check for corrosion on its blades and socket.  Try replacing the fuse, (they can go bad internally) see if that fixes it.  If NOT, then you have a problem with those wires or connectors, corrosion or looseness.  Check this by jumpering from the white wire going into the fuse to the solid blue wire going into the fan motor.  This by-passes everything.  Fan should run.  If it does, then there is a problem with wires or connectors or cooling fan switch. You say you've jumpered that switch so next suspects are wires/connectors.  Don’t be fooled by having “good voltage”.  A circuit can have “good voltage” when not under a load (meaning not drawing any amperage), but not be able to carry any current and make the appliance run.  Your voltmeter draws only a few milliamps.  If there is a bad problem with the wires, just run some new ones.

tested a bunch more and got readings all over the place.  what Nosmo said about the draw got me to thinking.  The fuse and housing looked pretty corroded, so I just cut it off.  hard wired there and everything works.  amazing....

I'll just go to the auto parts store and get another fuse connector to replace it.  I could cut the one off the other harness, but I'd rather not cut it apart for just that little thing.

thanks to everyone for your thoughts and input.  I can now go out on the lake tomorrow and drink in peace.  You guys rock!!!

Offline gpineau

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Re: cooling/fan questions
« Reply #14 on: August 03, 2019, 07:29:22 pm »
FYI if wanting to know for sure what the coolant temperature is ? I just did a check from stove top to freezer and recorded some of the readings.
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