MOTOBRICK.COM

TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: frankenduck on May 06, 2012, 12:39:41 PM

Title: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: frankenduck on May 06, 2012, 12:39:41 PM
Some people like to add a manual fan switch to their K bikes to help keep the bike's operating temperature down on hot days.  Adding a fan switch is really quite simple. The Motronic control unit triggers fan operation by grounding a blue/yellow wire that triggers the fan relay.  If you tap into that blue/yellow wire and have the switch ground that wire then the fan will come on.

Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: sh00ter on June 04, 2012, 11:45:33 AM
Does this grounding of the wire need to be done via relay or will a smallish (3a or so) switch work?  In other words is the full load of the fan going through that wire or are we just activating a relay which is then carrying the load of the fan?
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: frankenduck on June 04, 2012, 12:09:37 PM
blue/yellow wire that triggers the fan relay.

Very small load.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: sh00ter on June 04, 2012, 02:58:22 PM
blue/yellow wire that triggers the fan relay.

Very small load.

SO RTFP ...  :laugh :laugh   Thanks!
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: EJ on July 08, 2012, 09:30:27 PM
Does this also apply to an 85 K100RT?  My electrical box does not look like this.  The wire stated does not seem to control the fan.  I will try to post a pic tomorrow of my box.  I would like to do this mod as when it gets real hot out, my bike will shut down.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: frankenduck on July 09, 2012, 12:18:45 PM
No, an 85 K100's fan is triggered by the white temp relay.

What you'd need to do is add a relay that sends 12V+ the violet/yellow wire to the fan.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Inge K. on July 09, 2012, 06:21:24 PM
A second possibility you find at post #11 in this (http://www.motobrick.com/index.php?topic=2221.0) thread.

Inge K.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: EJ on July 11, 2012, 08:31:01 AM
That helps, also, when I put the violet/green wire to ground the fan comes on (as does the temp light on the dash)  But I think I'll try the +12vdc to violet/yellow.  I hope this cures my shut down when hot.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: frankenduck on July 11, 2012, 08:37:06 AM
If your bike shuts down when it warms up then that's typically a symptom of a failing Hall Effect sensor.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: EJ on July 11, 2012, 11:47:41 AM
It only shuts down when its really warm out (85+), but then if it is let set for 5-10 min, will start and run for undertimined time.  But again only when outside temp is high.  Otherwise, no worries. :confused: :dunno
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: frankenduck on July 11, 2012, 12:12:02 PM
It only shuts down when its really warm out (85+), but then if it is let set for 5-10 min, will start and run for undertimined time.  But again only when outside temp is high.  Otherwise, no worries. :confused: :dunno

Certainly sounds like the symptoms of a failing Hall Effect sensor.  Cary some water with you (cold if possible.)  When the bike quits pour the water on the HES cover plate to cool it down.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: EJ on July 11, 2012, 12:15:27 PM
I have heard of this, will this allow the bike to restart right away?
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: EJ on July 11, 2012, 01:35:59 PM
Are the hall effect avaliable (ebay, else where, price?)  Found on bike bandit for $500+
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: frankenduck on July 11, 2012, 02:04:55 PM
www.kbikeparts.com (http://www.kbikeparts.com) (me) - search for 12111459033
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: EJ on July 11, 2012, 03:26:12 PM
Running bench test;  Outside temp - 90 deg,  RPM - 2800,  Large fan blowing on Bike, ran for 40 min then shut down.  Cooled HES cover with 40 deg water til cover was cool to touch (10 min) bike will not start.  Run power to PUR/YEL wire for fan, run fan for 10 min then bike re-started.  Bike ran for 15 min then shut down.  Run fan only (no cooling HES cover w/water) for 10 min, bike re-started.  Suspect ICU overheating.  Thoughts?
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: EJ on July 12, 2012, 08:47:17 AM
Test continued:  7:30 PM,  Out side temp 77 deg,  rpm @ 2800,  large fan blowing on bike,  bike fan in normal mode,  ran for an hour w/no issues
 :dunno2: :dunno2:
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: BexarWolf on July 20, 2013, 09:03:49 AM
Just to be sure I'm splicing correctly, is this the right way to cut in a switch for the manual fan switch?

(http://img109.imageshack.us/img109/4698/ts65.jpg)
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Scott_ on July 20, 2013, 11:34:55 AM
Looks right to me..... Go for it.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Filmcamera on October 03, 2016, 11:41:40 AM
My fan is wired directly to the 87 pin on the fan relay so it is always on (it is the yellow and purple wire in the photo). 

I assume that means the whole temp circuit has been bypassed altogether.  I would like to try and get it back to how it is supposed to be and then add a manual override.  Where should I relocate that wire to put it back where it came from?

Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Inge K. on October 03, 2016, 02:00:48 PM
I have mentioned in another thread that you have two ABS warning light relays, while you should only have
one................both of the relays you have is placed in the wrong socket.
One of them is placed in the socket for the fan relay....that's why your fan is running all the time.

The ABS warning light relay is a NC relay, while the fan relay is a NO relay.....if your bike reaches a high
enough temp (with the continously running fan) the fan gonna stop, at the point it normaly should have
started.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Filmcamera on October 03, 2016, 05:44:18 PM
Inge when I replaced the blue fan relay with a yellow one as I think you had suggested all I did was blow a 15 AMP fuse...
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Laitch on October 03, 2016, 06:18:16 PM
Inge when I replaced the blue fan relay with a yellow one as I think you had suggested all I did was blow a 15 AMP fuse...
I think it would be helpful to post photos of the relay—the side with its identification and the side with the pins showing how you wired it.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Filmcamera on October 03, 2016, 06:47:43 PM
Well I haven't actually wired anything yet - the fan is always on which was done as a mod by a mechanic just after I got it because on the first ride home when it overheated  yet the fan never came on.

 I understood from from Inge that the fan is always on  was because the blue relay in the fan slot is a normally closed relay when it should be a normally open one. That would indicate that all the mechanic did was switch one type of relay for another. So I removed the blue relay from the slot and put one of the yellow ones in its place.  As soon as I turned the key the fuse blew.

On the relays I have there is no wiring diagram but I get a resistance reading of 114,2 ohms on the yellow one when I go from pin 85 to 86 and on the blue when I get 95.9 ohms when I go from the same pins 85 and 86.

Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Inge K. on October 03, 2016, 11:56:12 PM
Doesn't look like OEM relays, which explains a lot.....take a picture from the top also please.
Measure between 30 and 87 to determine if it's NC or NO relays.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Martin on October 04, 2016, 12:04:52 AM
HMC could refer to Honda Motor Company I've had a couple of Honda's and it looks vaguely familiar.
Regards Martin.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Filmcamera on October 04, 2016, 09:52:02 AM
I get no reading between pins 30 and 87 on either of the two relays, in fact no reading between any of the pins except 85 and 86.

The tops of them have nothing on them so I haven't posted a picture.

The only OEM relays in there seem to be, 61 31 1 459 676    SAFETY RELAY ABS, which is the big dark blue one on the top LHS and 61 31 1 459 677    RELAY - SCHLIEßER which is the black one to the right of it.

The other five, three yellow and two blue, are the type shown in the photos from an earlier post
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Inge K. on October 04, 2016, 10:57:42 AM
I get no reading between pins 30 and 87 on either of the two relays, in fact no reading between any of the pins except 85 and 86.

Then your blue and yellow all is NO relays, which it also should be.

Where you have a black OEM relay which ends on 677 (NO) it normaly should be a blue OEM relay which
ends on 675 (NC)......but if the ABS is disconnected/not active, that doesn't matter.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Filmcamera on October 04, 2016, 11:03:24 AM
Ok so I will have to actually change the way the fan is wired for it not to be on all the time.  Though at this point I am tempted to use the now empty ABS switch and just wire it in as a manual on/off switch.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: piptravels on April 09, 2018, 08:45:45 PM
Some people like to add a manual fan switch to their K bikes to help keep the bike's operating temperature down on hot days.  Adding a fan switch is really quite simple. The Motronic control unit triggers fan operation by grounding a blue/yellow wire that triggers the fan relay.  If you tap into that blue/yellow wire and have the switch ground that wire then the fan will come on.


Does this apply to a 1996 K110LT? I just got one and did my first 1,400+ mile trip and the manual switch looks like it might
be essential here in Southern California
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: johnny on April 09, 2018, 09:00:24 PM
greetings...

in socal i would be thinking of a johnny blanket... and of course go ahead and wire in that fan switch on your eleven hundert lt...

welcome to motobrick.com...

j o
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Laitch on April 09, 2018, 10:04:06 PM
Some people like to add a manual fan switch to their K bikes to help keep the bike's operating temperature down on hot days.  Adding a fan switch is really quite simple. The Motronic control unit triggers fan operation by grounding a blue/yellow wire that triggers the fan relay.  If you tap into that blue/yellow wire and have the switch ground that wire then the fan will come on.
Does this apply to a 1996 K110LT? I just got one and did my first 1,400+ mile trip and the manual switch looks like it might
be essential here in Southern California
The title of the thread is Adding a Manual Fan Switch to a 4 Valve K Bike. Are you aware that your K1100LT is a 4V K bike? It is, so this thread applies to your bike.

Austin, Texas isn't in Southern California. Are you commuting and store a bike there to ride when you're out there? K-bike do not store very well without certain precautions being taken.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: piptravels on April 09, 2018, 11:45:03 PM
I just rode from Austin to the high desert in southern California. I was not aware the K1100LT was a 4v K bike. But I am now, thanks. Not much on knowing every little detail...I just like to ride and fix things as they come up
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Laitch on April 10, 2018, 12:03:55 AM
I just rode from Austin to the high desert in southern California. I was not aware the K1100LT was a 4v K bike. But I am now, thanks. Not much on knowing every little detail...
Knowing whether your K is 2V or 4V isn't a little detai. Fix things as they come up must mean put air in the tires.

How about posting a few photos of your bike?
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: piptravels on April 10, 2018, 11:25:29 AM
Some people like to add a manual fan switch to their K bikes to help keep the bike's operating temperature down on hot days.  Adding a fan switch is really quite simple. The Motronic control unit triggers fan operation by grounding a blue/yellow wire that triggers the fan relay.  If you tap into that blue/yellow wire and have the switch ground that wire then the fan will come on.


Pardon my ignorance Frankenduck, so I would be switching the blue/yellow wire on the wiring harness to the green ground wire and this should give me the manual fan switch functionality?
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: piptravels on April 16, 2018, 12:54:44 AM
greetings...

in socal i would be thinking of a johnny blanket... and of course go ahead and wire in that fan switch on your eleven hundert lt...

welcome to motobrick.com...

j o


Hey Johnny, Thanks for the welcome. I switched the blue/yellow wire and the green/black (frame ground) and the fan comes on when the ignition is turned on but the engine is off. When I start the bike the switch no longer turns on the fan-defeating the purpose for me. Should I be using the smaller solid green wire instead?
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: Inge K. on April 16, 2018, 05:05:39 AM
I switched the blue/yellow wire and the green/black (frame ground)

Green/black is switched power........connect the blue/yellow to a frame ground, battery negative
or a Brown wire (which is frame ground) with the switch in between.
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: piptravels on April 17, 2018, 12:02:17 AM
Green/black is switched power........connect the blue/yellow to a frame ground, battery negative
or a Brown wire (which is frame ground) with the switch in between.


Thank you so much! I was under the impression that Green/black was a frame ground-live and learn. Will tap brown and report back :2thumbup:
Title: Re: Adding A Manual Fan Switch to a 4 Valve K Bike
Post by: The Mighty Gryphon on April 17, 2018, 08:00:22 AM
Easy way to remember.

Ground is also called "earth".  The earth is made of dirt, and dirt is often brown.