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Discussion Starter #1
1997 Blackbird
120,000 km

This seems to be a bit of a common topic from the search results. My fan did not kick in on a recent ride. The temperature gauge almost hit the red mark.

The fuse is good. There is coolant in the reservoir. The fan is not physically stuck.

What else can I check? I have the bottom left fairing off.

Ideally, I'd like to test out the fan with a manual switch but can't find some sort of step by step diagram or tutorial to accomplish that.

If the manual switch works to turn on the fan, I'll leave it at that and call it a day. I just need some sort of tutorial for it.

Thanks
 

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With this many miles I wouldn't be surprised if you have a ground problem, which seems to be common on these machines. Anyway, try jumping the thermostat which I believe is screwed into the radiator. Ignition on, this should turn on the fan If that fails, unplug the fan and try to get it to run with hot wires direct from the battery. Don't recommend manual switch as thermostat will do the job more reliably.
 

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As Fizz has said. Jumper the rad connector first with the key on fan should fire.
 

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At the large sensor on the lower left side of the radiator you'll find a rubber booted plug. You might be able to see it through the Duct. Pull it and put a piece of insulated jumper wire into the 2 connectors inside that boot. Turn the key on and the fan should spin up.
 

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Discussion Starter #6
At the large sensor on the lower left side of the radiator you'll find a rubber booted plug. You might be able to see it through the Duct. Pull it and put a piece of insulated jumper wire into the 2 connectors inside that boot. Turn the key on and the fan should spin up.
thanks.
 

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Discussion Starter #7
I cant get the fan to spin
I followed the directions about jumping and I also used my multi meter like in this video


I know it's for a CBR F3 but I assume the parts are similar.

The fan doesn't spin when I jump it and I'm only reading about 1.84 V when the key is on.
 

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Then I'd do as fizzy suggests next and run couple of wires down to the fan and see if it'll come up. I'm suspecting that because your only seeing a very low voltage. That your fan isn't being triggered. Your going to have find a wiring diagram. Or better yet a manual. See if it has a troubleshooting section on the fan and follow it out.
 

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Just watched that video. Your going to definitely need a wiring diagram. I am suspecting your not getting the voltage to the fan. So now your going to have to find out the supply line I am suspecting if your system is set up like this. Then either the fuse is blown and or you have a short or open wire in the harness that feeds that sensor. If the circuit woks the way I suspect the fan has power at all times and that switch only closes completing the ground path when the engine gets to hot. The fact that your only seeing 1.84 v makes me suspect the fuse first.
 

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"I cant get the fan to spin "
You unplugged the fan and touched 2 wires direct from the battery to the terminals on the fan and it didn't spin? Also, where exactly is the 1.84V when the key is on?
 

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Discussion Starter #11
The low voltage was measured between the small connector that connects the fan thermo switch and the neg batt terminal.

I was unsuccessful to directly power the fan though it's likely I'm doing it wrong.
 

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Not intimately familiar with a carby and am assuming fan thermo switch has 1 wire. If so, you wont find any voltage there. It is a switch that completes the circuit when it heats up. Try again to get the fan to run with jumper wires, also double check all the fuses. Do all the other electrics work ok, lights, signals etc?
 

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Discussion Starter #13 (Edited)
ill try to jump the fan later today after work. everything else on it is fully functional and all fuses are good.

I'll also follow this procedure from the manual:

129500
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Discussion Starter #14
well. no luck at all trying to jump the fan. i checked the ground wire from the fan to the rad, as well as the connection from the fan to the wiring harness. they all seem good

so from here, i would imagine either the fan is pooched or there is an issue with the wire somewhere along the way.

I did have issues with my ignition wiring which required some soldering

Is it possible that would somehow interfere with the fan / temperature sensor?
 

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Matthew yes it could well be an issue. The BB's take power to the fan off that switch separately. But if bringing power from the battery to the fan motor doesn't make it fire then chances are your fan is duff.
 

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Discussion Starter #16
ok i guess this will be my last post on the matter, until the issue is solved. I'm inclined to think the wiring issue I had with the ignition switch might be related because the fan seems to be controlled by the ignition switch.

I had to solder the ignition wire back onto the ignition barrel, The bike starts and runs now, but I can't help but think that may be the cause of my issue

129531
 

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When you roll the key on, both those lines should go hot. Check them again with your meter. Key on all 3 should see battery voltage.
 

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Pull the fan motor fuse, and ignition on, check for voltage there.
OK to keep posting, happy to help if we can.
Edit: one probe of multi meter on neg batt terminal, other probe on fuse holder (check both sides).
 

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Discussion Starter #19
Pull the fan motor fuse, and ignition on, check for voltage there.
OK to keep posting, happy to help if we can.
Edit: one probe of multi meter on neg batt terminal, other probe on fuse holder (check both sides).
almost nil. it was either 1v or .1v. ill have to go double check but not seeing the battery voltage
 

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Agree with fizz one side if that should be hot. Your going to have to check at the switch. If battery voltage is good there. You've got a broken wire in the harness that feeds that fuse position.
 
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