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Discussion Starter · #1 ·
I've done what I can to test the gauge, and I can't get it to register anything when connecting a ground to the lead. Seems to be shot. But also, the radiator fan is not kicking on either. I drained the coolant, refilled, bled, still no temp gauge, no fan. Tested the fan motor, it works.

I guess my question is, before I bust out the ohmmeter, can the water temp sensor malfunctioning cause the radiator fan switch to not work, or vice versa? I'm scratching my head as to how both of these things stopped working.

Could there be an air lock further down in the system, creating a void by the fan switch? If so, is there a more aggressive way to bleed the system than the bleeder screw? A lot of questions, I know, I'm just at a loss at the moment.
 

· ..have a vulcan good day!
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I've done what I can to test the gauge, and I can't get it to register anything when connecting a ground to the lead. Seems to be shot. But also, the radiator fan is not kicking on either. I drained the coolant, refilled, bled, still no temp gauge, no fan. Tested the fan motor, it works.

I guess my question is, before I bust out the ohmmeter, can the water temp sensor malfunctioning cause the radiator fan switch to not work, or vice versa? I'm scratching my head as to how both of these things stopped working.

Could there be an air lock further down in the system, creating a void by the fan switch? If so, is there a more aggressive way to bleed the system than the bleeder screw? A lot of questions, I know, I'm just at a loss at the moment.
There are a few different methods of draining/refilling/bleeding the any air from coolant system...perform such if over heating...the gauge is a separate issue...sounds electrical to me...maybe a connector problem...but yes, If the sensor isn't sensing (inoperative) then the gauge cannot register...I am unsure if u properly tested gauge...
 

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Discussion Starter · #3 ·
I followed the manual to check the gauge. Pulled lead off of water temp sensor, connected auxiliary wire to lead, turned key on, grounded the wire, and no gauge movement.

With no fan, no temp gauge, I'm wondering if they are on a circuit, one going out causes the other to go out. The fan has its own relay, so I doubt that.

HMMM...Thanks for the thoughts William.
 

· ..have a vulcan good day!
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I followed the manual to check the gauge. Pulled lead off of water temp sensor, connected auxiliary wire to lead, turned key on, grounded the wire, and no gauge movement.

With no fan, no temp gauge, I'm wondering if they are on a circuit, one going out causes the other to go out. The fan has its own relay, so I doubt that.

HMMM...Thanks for the thoughts William.
Be aware, 0 - 12 V to the gauge will register on the gauge 0 - max temp (as if a voltmeter) ....12 volt on the gauge should have pegged the meter...
Just say in'
 

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Discussion Starter · #5 ·
Be aware, 0 - 12 V to the gauge will register on the gauge 0 - max temp (as if a voltmeter) ....12 volt on the gauge should have pegged the meter...
Just say in'
Yeah, that's why I think it bit the dust, no pegging when I closed the circuit. I don't know what would have killed a gauge, maybe a spike from the r/r or something. I'm going to test the sensors tomorrow with an ohmmeter. I'll just go to bed angry tonight.
 

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I don't know how savy You are on the bike, but the temp senser is under the feul tank close to the radiator cap. The heat senser for the the fan is the one on the left bottom of the radiator.
 

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Discussion Starter · #7 ·
I don't know how savy You are on the bike, but the temp senser is under the feul tank close to the radiator cap. The heat senser for the the fan is the one on the left bottom of the radiator.
Yeah, I know that much. I finally got the temp gauge to peg after crimping a new terminal on the lead, so I know that isn't the problem. I'm guessing that there is/was some sort of air lock jamming my cooling system, not letting coolant to the sensors. I've had to bleed it/run the engine 3 times before it finally filled the radiator fully.

Weekend is coming so I'm sure I'll get it sorted out then. Thanks.:beerchug:
 

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you can ground the wire going to the sensor in the bottom of the radiator and check to see if the fan circuit is good .The fan should run with the wire grounded and the key on.If it doesn't then unplug the fan itself and run a couple of leads to the battery and if it runs the problem is in the fan relay in the JB or associated wiring.

I replaced a perfectly good fan motor once without checking the relay circuit this way,money spent ,lesson learned the hard way.
 

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Discussion Starter · #9 ·
you can ground the wire going to the sensor in the bottom of the radiator and check to see if the fan circuit is good .The fan should run with the wire grounded and the key on.If it doesn't then unplug the fan itself and run a couple of leads to the battery and if it runs the problem is in the fan relay in the JB or associated wiring.

I replaced a perfectly good fan motor once without checking the relay circuit this way,money spent ,lesson learned the hard way.
I did that, the fan circuit and motor work fine. I need to test the sensor by pulling it and checking the resistance with it in hot water.
 

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when more than one electrical component stops working at the same time, i would put my money on a ground wire somewhere. similar thing happened to me, most of the non-essential circuits on my bike went dead, blinkers/warning lights/fuel gauge maybe some other stuff, neutral light went dead, it was a bad ground up in the headlight bucket, one of the plugs. took me a while to figure it out. you might want to start checking all the grounds and the white plugs too. the plugs can get corroded inside, or become loose. mine was simply loose, the hook came undone somehow. funny how much you can miss the neutral indicator at red lights...
 

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Discussion Starter · #12 ·
Just to update, I noticed that my fan is kicking on. It probably wasn't getting warm enough, because it's still in the 50's and my commute is 90% interstate. I'm glad the fan is kicking, because the coolant temp sensor isn't working. The gauge tested out fine, the sensor ohm range tested out fine, the thermostat checked out, and all of my other gauges and lights are good to go. I don't know what the hell is going on. I'm guessing the lead on top of the sensor isn't contacting the wire well enough. I'll probably try soldering it on there before I just buy a new one.
 

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Just to update, I noticed that my fan is kicking on. It probably wasn't getting warm enough, because it's still in the 50's and my commute is 90% interstate. I'm glad the fan is kicking, because the coolant temp sensor isn't working. The gauge tested out fine, the sensor ohm range tested out fine, the thermostat checked out, and all of my other gauges and lights are good to go. I don't know what the hell is going on. I'm guessing the lead on top of the sensor isn't contacting the wire well enough. I'll probably try soldering it on there before I just buy a new one.
Wait no.. What happened????😭
 
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