K100RS fan hasn't been coming on (prob u/s since I got the bike 3 years ago.
Since i have the LH upper fairing piece and the tank off to deal with another issue, I'd like to test it and 
see if it will switch on. Can turn the fan blade although not running freely so :
1 - can i lube the shaft in situ with WD40 using a tube and where?
2 - how can I determine if the temperature sensor is the problem
3 - If it's not the sensor, how can I test the fan without removing it. 

Bike dropped down to 3 cylinders (but could have been two) Simultaneously tacho went AWOL. 
Suspicion that it could be a coil issue but first i checked that ignition control unit plug was firmly seated.
Turned coils 'upside down" and all connectors clean and seating properly. These are the old all black coils so I understand that they could be originals. Have a No 1 and 4 coil that I got off a wrecked RT. Since the tacho impulse goes through this coil, can i just do a swap.

My electrical expertise is currently limited to getting 3 pin plugs into wall sockets so any directions will have to be in "dummies' format, otherwise we might have a Pauline "please explain" session.

werewasi wrote:K100RS fan hasn't been coming on (prob u/s since I got the bike 3 years 
1 - can i lube the shaft in situ with WD40 using a tube and where?
2 - how can I determine if the temperature sensor is the problem
3 - If it's not the sensor, how can I test the fan without removing it. 
we might have a Pauline "please explain" session.

Lubing the shaft with WD 40 will not be of much use.
Here is the procedure to review while waiting for Pauline. 

werewasi wrote:
1 - can i lube the shaft in situ with WD40 using a tube and where?

Hey!
Do not use WD40, not good at all!
You should use Staburags instead, you will not need much, 10g could last a Lifetime.

Staburags EBay



Cheers

I think he means the shaft of the fan not the drive shaft. No you wont be able to do anything with the fan in situ. They are a very cheap and nasty piece of work and I would expect much better of BMW. The 7" SPAL is a good replacement.

To check the fan remove the temp sensing unit from the relay box under the tank and connect the green/brown, Terminal 15 and violet/yellow terminal A2 wires together.

crikey dave

your in at under the tank

did you do as we discussed  ?

1 take the connector apart from the under tank ecu ...get the contact cleaner from supercheap  as I reminded you to do
get the tooth brush and clean both sides of the connectors at the ecu ...flushing out the crap ...blasting the tooth brush with the cleaner spray then scrubbing the contacts ...on both sides with the wet with cleaner fluid tooth brush
2 find the hall effect connector cable ...right hand side of the frame near the ecu ..take it apart and clean both sides of that as well... it should have 5 pins and a socket to match

 for the fan

you need to remove the radiator assembly to properly lubricate the fan assembly ...front and back

but you can remove the right hand side lower fairing to gain access , however you may  need to remove the top of the aircleaner box to gain access to the fan motor rear bearings ...but it can be done with air cleaner box in situ ..there is a plastic cap over the rear of the fan motor  which when removed will allow you to lubricate the rear bearings ...which seems to be the most accessible  location to spray first off ...wd 40 will swamp the bearing with fluid which is likely to loosen the shaft from the bearing ...but is not a good lubricant ...after you have it turning use a light mineral based oil  .

did you actually attempt to rotate the fan blades ? were they easy to turn ?
you can get a stick and rotate the fan blades from the lower right fairing breather vents towards the rear of the fairing ...tricky but possible

the link that laitch posted has a away of turning on the fan ...after you have established that the fan actually is turning freely




for the coils and spark plugs

did you measure the leads through the coils as we discussed ...using your autoranging multi meter ?

remember it should be about 20,000 ohms or less

also remember that we discussed that if your tacho doesn't function that the 1-4 coil is probably not getting the right signals to switch on off ..and then suspect the hall sensors - icu computer under the tank ...unless you measure that the 1-4 coil is short circuit

the primary of the 1-4 coil should be about 2.6 ohms  so your measuring the blue - black wire connector on the coils and the yellow green  to get the 2.6 ohms  tell us if it measures below this

good luck mate

Laitch wrote:

werewasi wrote:K100RS fan hasn't been coming on (prob u/s since I got the bike 3 years 
1 - can i lube the shaft in situ with WD40 using a tube and where?
2 - how can I determine if the temperature sensor is the problem
3 - If it's not the sensor, how can I test the fan without removing it. 
we might have a Pauline "please explain" session.

Lubing the shaft with WD 40 will not be of much use.
Here is the procedure to review while waiting for Pauline. 

As mentioned in one of the posts on the site Laitch refers to, the numbering is different to my diagram at least.
http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/efi-web%20page/relay-tray.jpg (from our revered Crazy Frog) shows the layout of the relay tray under the back of the tank, with the top of the diagram towards the front of the bike.
From the diagram on the page Laitch refers to, remove the Temperature switching unit and just join the battery positive to the A2 terminal on the relay socket with a spare piece of wire. The fan should run.

If the fan doesn't run, or runs slowly or erratically, no alternative to removing the fan, and dismantling at least the back end. I hope yours isn't like mine was, with melted brush mounts. If so, new fan motor.  There are some posts which can be found showing installing an alternative unit. A new motor can be obtained from Euro Moto Electric (EME) in the states much cheaper than going to BMW. (That was my path.)

If the brushes and mounts are OK, dismantle, clean and lubricate the bearings with light machine oil. WD40 or the like might make a difference in the short term, but sooner or later you'll need to dismantle it.

Bill

PS Without me realising, Rick G and Charlie 99 added their valuable 2 cents worth before I finished my contribution. They're always worth listening to.  

Rick,
So if i go to the relay box under the back of the tank, is the temperature sensing unit marked as TSU or how else do i recognise it.
You say -  Terminal 15 and violet/yellow terminal A2 wires together. 

but Laitch's MOTOBRIKER post says A2 and 45!!!!!!!!!!!! 
So I take 15 and A2 off and join them, bypassing the TS. Correct?

Is there a "Ks for Dummies" book out there?

Charlie,
yes, i did what you said re cleaning but it was the ICU and plug. You're using the term ECU so i'm confused.

On the RH side downstream fr the ICU is a half round white plug with 4 wires, not 5, red, blue, purple and green. Is this the HE sensor plug? If so i'll clean it too.

The fact that the fan actually turns rather than being frozen, makes me want to try and see if it will run rather than removing and replacing with the SPAL unit that Rick talked about.
I'll take the top off the airbox and lube from the back after i've established that it will actually run properly.
Heard you loud and clear about not using WD40.

Now that i've got the coils inverted with the connectors topside, I'm not sure about measuring the resistance.
I've been looking (and couldn't find it in the DOWNLOADS) for a pic of them so that i can identify the tabs.
Without a pic, I'm flying blind.
What do you mean - did you measure the LEADS through the coils 
I'm scared that i'll fry something like the ICU if i stuff it up and think that I'd be better just to bolt the spare 1 and 4 coil on and see what happens.

Bill
Quote 
From the diagram on the page Laitch refers to, remove the Temperature switching unit and just join the battery positive to the A2 terminal on the relay socket with a spare piece of wire. The fan should run

I can understand that and will do it.

Easier to just use a jumper wire to bridge #15 to #A2 as Rick said.

werewasi wrote:K100RS fan hasn't been coming on (prob u/s since I got the bike 3 years ago.
Since i have the LH upper fairing piece and the tank off to deal with another issue, I'd like to test it and 
see if it will switch on. Can turn the fan blade although not running freely so :
1 - can i lube the shaft in situ with WD40 using a tube and where?
Throw away your can of WD40 Dave!!! I reckon if its turning, good chance it'll be ok.
2 - how can I determine if the temperature sensor is the problem
With the bike running on the centre stand it should reach operating temp fairly quickly and shortly after, the fan should come on before the red temp warning light.
Alternatively you could measure Ω between the white/green wire at the temp relay and earth. I can't remember which pin that is. I think you should get a reading the same as when measuring the other side of the temp sensor at the FICU plug which is 2.5kΩ at 20ºc and less that 300Ω at 80ºc and above. Someone correct me if I'm wrong on that.

3 - If it's not the sensor, how can I test the fan without removing it. 
Follow Rick's advice above. You'll find the schematic for the electrical box in the 'Trouble Shooting page which links off the Portal page.

Bike dropped down to 3 cylinders (but could have been two) Simultaneously tacho went AWOL. 
Suspicion that it could be a coil issue but first i checked that ignition control unit plug was firmly seated.
Turned coils 'upside down" and all connectors clean and seating properly. These are the old all black coils so I understand that they could be originals. Have a No 1 and 4 coil that I got off a wrecked RT. Since the tacho impulse goes through this coil, can i just do a swap.
Unless I'm totally mistaken and I can't read a wiring diagram, the tacho pulse does not go through the coil. It only loops off the spade connector on the coil and up to the tacho. If your tacho went out it'd be something upstream like the ICU or HES and/or wiring /connectors in between which is consistent with losing power on 1+4 cylinders. If you have a spare set of coils, just swap them and see what happens. I doubt it will fix the problem.

My electrical expertise is currently limited to getting 3 pin plugs into wall sockets so any directions will have to be in "dummies' format, otherwise we might have a Pauline "please explain" session.

In the Trouble Shooting page you'll find the layout for all the plugs under the tank

One other thing you can do which might save a lot of effort; grab hold of the cover on the back of the fan motor and wriggle it until it comes off (it's a snap fit). Check for melted brushes; if they look okay then you're into a system deep-dive

And while I've got your attention Dave: https://www.k100-forum.com/t12149-india-the-easy-way

Here is a diagram of which relay is where

On my K100 it was the brush holders that melted.  (Who would actually use a low temperature plastic in an automotive application besides Bosch?)

The Spal retrofit is relatively inexpensive, moves more air, and when installed per this thread:  http://www.motobrick.com/index.php/topic,4313.0.html

Go down to post #18 by Roadbandit on December 20, 2014.

http://www.ebay.com/itm/Spal-Fan-Assembly-6-5-inch-12V-/111530449235?hash=item19f7bb9953:g:5AUAAOSwjVVVxPqk&vxp=mtr

"Who would actually use a low temperature plastic in an automotive application besides Bosch?)"

Um...Lucas?

Oh behave!

So, we find Bosch guilty of stealing trade secrets...

Ah I have fond memories of LUCAS the Prince of Darkness and my 1959 Bonneville where it was very common to see the rider lighting a match to see if the headlight was working.

Chocolate wrote:

werewasi wrote:
1 - can i lube the shaft in situ with WD40 using a tube and where?

Hey!
Do not use WD40, not good at all!
You should use Staburags instead, you will not need much, 10g could last a Lifetime.

Staburags EBay



Cheers

Legendary, thanks Chocolate!  Even though this was off topic, I haven't come across the silicone plug inside the drive shaft idea before.  I'll be using that when the time comes 

The fan to start with -

Thanks Rick for that relay box layout -  without it i couldn't identify the various relays.
Pulled what I think is the temp sensor relay on LHS middle attached by 8 mm bolt. Has 8 pins (pic along soon) but it does not look like the one in the Laitch link and has not got a pin numbered 15 (or 45) or A2.
Got power fr battery and tried all the sockets. Fan did not start.

Next attempted to access plug on top of fan. Cannot disconnect but it's possible there's a securing clip that i can't see.
Seems like the best idea is to remove the fan and test and lube. If no good will use SPAL fan.

Now 'ignition" 
Charlie - tested resistance  One 3600 and the other 3300. Tried spare and got nothing so it seems as if I was doing it right.
Attempted to measure plug leads and because meter probe won't go into plug holder i inserted an allen key and clipped it to the probe. Set meter on K ohms but got zilch on all four. Is this the way that Oppenheimer would have done it?

Put #1 lead on front and #4 at rear of coil. #2 on front and #3 on rear. Everyone agree?

So plan B - Have de oxited the Jtronic unit plug. Will stick the tank back on and start it up.

If it does run better,then i’ll also put new plugs in but don’t want to do this until i’ve found the fault.
I have not found that Hall Effect sensor plug that i asked you about 


Bert
thanks for the links and help.

The temp sensing relay is on the right side.

This layout may more helpful.

Yes it is on the RHS because i checked again. Then i dived for the laptop and was going to pull down the post before any of you saw what i'd written (you stoopid boy).

That was the bulb sensor relay i examined and i had my mate Ray Fisher here at the time as honary head honcho.Even he didn't twig. Embarrasing!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

So I'm going to put my white anti static zoot suit and booties on , and go down and do the test again.

RESULT
Power fr battery to 15 and fan doesn't move.

Questions
Why does bulb not light up on tester when on pin 15. It does if i ground it on the motor.
Why does it light up on E.
Why does it just glow dimly on A2 (the power source pin.

Just askin

Power should go from battery to A2.  

Bill

Dai wrote:One other thing you can do which might save a lot of effort; grab hold of the cover on the back of the fan motor and wriggle it until it comes off (it's a snap fit). Check for melted brushes; if they look okay then you're into a system deep-dive

And while I've got your attention Dave: https://www.k100-forum.com/t12149-india-the-easy-way

Tks Dai,
have started and getting my mapbook out to just re orienatate myself with location of Kalka.

Looking forward to getting your impressions of the Enfield. Don't know if you read my blog but mine was a POS

under tank wiring connections locations



the hall sensor connections are usually inside a rubber boot

hope that helps

werewasi wrote:Tks Dai,
have started and getting my mapbook out to just re orienatate myself with location of Kalka.

Looking forward to getting your impressions of the Enfield. Don't know if you read my blog but mine was a POS

I did read your blog and our experiences were chalk and cheese. Our bikes were brilliantly maintained - someone did sell you a POS.

{on topic} The connector to the fan is secured by a couple of ears with a molded security pip on the inside. Push the ears outwards and the block should come apart.

Thanks for that pic Charlie - exactly what i needed and it's apparent that what I was looking at was #6 the temperature sensor plug. Will now deoxit and clean #3.

What did you make of the coil figs ?

Am going to put a screw in the plug nipple (nut) and drop into plug end of HT lead, then this may give better contact with meter probe.

yeah good start 'you wont get any sensible readings until you do

I don't know what you were measuring before ..