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1Back to top Go down    Cooling fan *fixed* on Sat Apr 23, 2016 4:01 pm

riddle the sphinx

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Can anyone confirm, deny or add to the following tests for the cooling system to find fault:

at the fan relay switch,
1) temp sensor - resistance test between E & 9 looking for circa 2,000 - 3,000 ohms cold.
2) temp warning light - bridge 31 & A3
3) fan motor - bridge 15 & A2



Last edited by riddle the sphinx on Sat Apr 30, 2016 9:42 am; edited 1 time in total


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2Back to top Go down    Re: Cooling fan *fixed* on Sat Apr 23, 2016 7:50 pm

Holister

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@riddle the sphinx wrote:Can anyone confirm, deny or add to the following tests for the cooling system to find fault:

at the fan relay switch,
1) temp sensor - resistance test between E & 9 looking for circa 2,000 - 3,000 ohms cold.
I've not done this test but you would need to measure resistance between #E and #31 (earth) or anywhere on the engine. #9 is power. I'm not sure what the resistance is across that sensor so I'd be keen to hear what you get. I did ask that question on another thread recently but got no answer so I'm assuming no one knows. I would say its probably the same as for the test at the FICU pins #10 & #13 - 2.5k ohm
2) temp warning light - bridge 31 & A3 Correct. The Temp warning light has power to it so bridging to #31 (earth) would light it up with ignition on.
3) fan motor - bridge 15 & A2 Correct. These are for the fan switch inside the temp controller. Check fuse #7
Also pin #9 comes off fuse #6.... power to the temp controller

good luck. What fault are you trying to track down?


__________________________________________________
1988 K100RT VIN No. 0094680
1989 K100RT VIN No. 0097367 (naked)
1996 K1100RS VIN No. 0451808
Fuel: 95 Octane
Engine Oil:Nulon Full Synthetic 15W50
Gear Box Oil: Nulon Synthetic 75W90
    

3Back to top Go down    Re: Cooling fan *fixed* on Sun Apr 24, 2016 6:33 am

riddle the sphinx

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Kaptain Holister wrote:
@riddle the sphinx wrote:I've not done this test but you would need to measure resistance between #E and #31 (earth) or anywhere on the engine. #9 is power. I'm not sure what the resistance is across that sensor so I'd be keen to hear what you get. I did ask that question on another thread recently but got no answer so I'm assuming no one knows. I would say its probably the same as for the test at the FICU pins #10 & #13 - 2.5k ohm
"measuring the resistance between E and 9 will read the resistance of the temp probe. 'Normal' cold bike readings I've seen are (+/-) 2,200 ohms. On colder days closer to 3,000 ohms. If you warm the bike up, quickly remove the tank and take a reading, expect to see about 520 ohms. Readings in this range seem to confirm a normal temperature probe function."
Jeff Dunkle - ibmwr.
Also pin #9 comes off fuse #6.... power to the temp controller

good luck. What fault are you trying to track down?
Cooling fan is not coming on, I ran at idle for 12 mins without switching on.


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4Back to top Go down    Re: Cooling fan *fixed* on Sun Apr 24, 2016 6:37 am

Dai

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Pull the back off the motor and check the brushes. The cover just clips in, so a slight rocking motion and a quick pull should release it easily. My bet is that you have the common meltdown in there.


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'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
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5Back to top Go down    Re: Cooling fan *fixed* on Sun Apr 24, 2016 6:46 am

riddle the sphinx

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cheers dai,

I will check that out as well but would like to check over everything else at the same time just for the sake of it.


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6Back to top Go down    Re: Cooling fan *fixed* on Sun Apr 24, 2016 1:18 pm

Holister

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Kaptain Holister wrote:
@riddle the sphinx wrote:Can anyone confirm, deny or add to the following tests for the cooling system to find fault:

at the fan relay switch,
1) temp sensor - resistance test between E & 9 looking for circa 2,000 - 3,000 ohms cold.
I've not done this test but you would need to measure resistance between #E and #31 (earth) or anywhere on the engine. #9 is power. I'm not sure what the resistance is across that sensor so I'd be keen to hear what you get. I did ask that question on another thread recently but got no answer so I'm assuming no one knows. I would say its probably the same as for the test at the FICU pins #10 & #13 - 2.5k ohm
"measuring the resistance between E and 9 will read the resistance of the temp probe. 'Normal' cold bike readings I've seen are (+/-) 2,200 ohms. On colder days closer to 3,000 ohms. If you warm the bike up, quickly remove the tank and take a reading, expect to see about 520 ohms. Readings in this range seem to confirm a normal temperature probe function."
Jeff Dunkle - ibmwr.
As far as I can determine, the pin number you refer to in that article appears to be incorrect.
The temp sensor has two connections. One to earth thru the threaded body of the sensor to the engine block. The other connection goes to pin #E on the temp controller.
The Temp controller earths thru pin 31 as far as I can see from the schematics. I thought it would make perfect sense to test for resistance across the sensor connections at Pin #E and earth (or Pin #31). I'm sure someone will correct me if that's not right.
This test is done on the female connector (socket) with the Temp Controller removed

As I said above, Pin #9 supplies power from the FI relay thru Fuse #6 to the temp controller.
I'm away from home at the moment and don't have my DMM with me but if I can get hold of one tomorrow I'll whip my tank off and do a test to confirm but I can't imagine you'd get a reliable reading (if at all) for the sensor from Pin #9



Last edited by Kaptain Holister on Sun Apr 24, 2016 6:51 pm; edited 1 time in total (Reason for editing : deleted irrelevant parts of previous post)


__________________________________________________
1988 K100RT VIN No. 0094680
1989 K100RT VIN No. 0097367 (naked)
1996 K1100RS VIN No. 0451808
Fuel: 95 Octane
Engine Oil:Nulon Full Synthetic 15W50
Gear Box Oil: Nulon Synthetic 75W90
    

7Back to top Go down    Re: Cooling fan *fixed* on Mon Apr 25, 2016 5:20 am

Holister

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I was able to do this test this afternoon with the engine temp around 30 to 35oC.
While I measured something around 2.4 kilohm between Pin #9 and #E a conclusive measurement from Pins #E and #31 of 1.8 kilohm matched the coolant temp as indicated on the temperature graph on the troubleshooting page. To confirm that reading I also measured the resistance at the FICU (#10 & #13) for the other side of the sensor and it only varied by 15 ohms.
I have no idea what was being read off 9 & E but I'm pretty sure it is nowhere near correct.

Pin #E and #31 are the correct pins for that test

Cheers


__________________________________________________
1988 K100RT VIN No. 0094680
1989 K100RT VIN No. 0097367 (naked)
1996 K1100RS VIN No. 0451808
Fuel: 95 Octane
Engine Oil:Nulon Full Synthetic 15W50
Gear Box Oil: Nulon Synthetic 75W90
    

8Back to top Go down    Re: Cooling fan *fixed* on Mon Apr 25, 2016 5:27 am

riddle the sphinx

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excellent. thank you very much for this......... whaurs me spanner.


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9Back to top Go down    Re: Cooling fan *fixed* on Sat Apr 30, 2016 9:51 am

riddle the sphinx

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Ok, so finally solved the issues with the cooling fan.

After birdgeing the connectors on the fan - no worky.
I did as Dai suggested and removed the rear cover on the fan, blasted with wd40 and turned by hand for a while, tried again and it started to work weakly and intermittently. so with the bridge fixed in place I blasted with contact cleaner until she ripped into full life. happy days.

however still no worky idling for 12 mins....so...

...replaced the temp sender unit and now all is good.

Thanks for your help guys.


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10Back to top Go down    Re: Cooling fan *fixed* on Sat Apr 30, 2016 9:53 am

charlie99

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yay good solve


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11Back to top Go down    Re: Cooling fan *fixed* on Sat Apr 30, 2016 12:14 pm

Dai

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Very Happy


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'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

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