How to test fan relay on K1100LT with black fan relay (not standard white relay)

[obsessed]

Working on a 1995 K1100LT in Washington State.


I am unable to test the fan relay as described at http://www.ibmwr.org/ktech/fan-diagnosis.shtml as this bike does not have the white fan relay box.    Anyone here know how to do test the fan on this bike?   My internet searches have been unsuccessful.  I believe the fan relay is the second little box down on the left (see attached photo).

Thanks.

[rbm]

from http://www.k11og.org/forum/viewtopic.php?t=2110:

There is a black 3 pin diagnostic connector on the left side of the bike above and to the left of the battery, you will need to remove the side cover to gain access. This connector will have a blue plastic weather protector connected to the open end. Pin #1 will have two Brown/Black wires, Pin #2 will have one Brown/White wire and Pin #3 one Brown/Green wire. Here are the pin functions for this diagnostic connector.

Pin1: Motronic Diagnostic Fault Code Read-Out and Fan Test Activation
Pin2: ABS Diagnostic Fault Code Read-Out and RESET
Pin3: Motronic Diagnostic Activation of the Throttle Position Sensor Test.


To test the fan circuits, Ignition ON, Engine OFF, ground pin #1 for 10 seconds. The fan will cycle intermittently and the temperature warning lamp (or the Test LED, if connected) will flash 3333.
This indicates that the fan test is in progress. This test will continue to run until the ignition is switched off.


NOTE: Fan Test for Motronic 2.2
John from Down Under adds this:


"Fan Test works on Motronics 2.2"


1. Ignition must be OFF
2. Ground Pin 1
3. Turn ignition ON
4. Count to ten (1 Mississippi, 2 Mississippi,...........)
5. Unground Pin 1
6. Fan will intermittently run until ignition is turned off

[obsessed]

Thank you, rbm!

[Lucas1983]

Hello everyone! Proud owner of the 1993 k1100lt.  I believe I have done as much research as I could on this topic which lead me to this post.
I did the test and the fan works, I am not getting the 33333 on my cluster.  However, the fan still doesn’t turn on after 20-30 minutes of ridding.  Could this be the temp sensor? What is the next step after testing the fan?
Thank you.

[frankenduck]

Put a 9V battery to pins 85 & 86 and listen for a click.

or

Put a 9V battery to pins 85 & 86 and test for continuity between 30 & 87.

Or ground the blue/yellow terminal of the socket. (The Motronic grounds the blue/yellow wire to turn on the fan.)

[Laitch]

Hello everyone! Proud owner of the 1993 k1100lt..  However, the fan still doesn’t turn on after 20-30 minutes of ridding.  Could this be the temp sensor?

Welcome to the site, Lucas.

The fan only turns on to keep the engine from overheating. If the engine isn't idling for 15 minutes in moderate temperature or lugging along in stop-and-go traffic, the fan is unlikely to come on when at speed in Chicago this time of year. Idle it for 15 minutes or so to see if that activates it. Also, try moving the fan blades with a dowel or screwdriver to verify that it moves freely.

[frankenduck]

The fan won't come on when you're riding. Only when you are stopped or in stop-n-go traffic as Laitch pointed out.

The only way to test it is to let the bike sit and idle. If the fan doesn't come on and the temp warning light in the cluster comes on then there's an issue.

If the temp sensor is bad so that the warning light doesn't come and the bike is overheating then the radiator cap under the right front of the tank will blow before the engine is damaged. (Just like a car.) It blows out both coolant and steam so it's very obvious when it happens.

Here's how the cooling system works:

185F - Thermostat opens
221F - Fan comes on
232F - Warning light comes on
248F - Radiator cap blows

[Lucas1983]

Thank you everyone for the input.  I used the testing plug under the seat (the one with the blue weatherproof cap) to test the fan. It turns over on and off as described in the testing step.
I also let the engine idle ( on the center stand without any movement)for about 10 minutes but that was last month when it was still a bit cold in Chicago.  Maybe it wasn’t long enough. I will try again, this time longer and will report back.