Test fan without removing gas tank? K100lt

[Arredondo1]

Hey guys just picked up a k100 lt. I did the 15 minute test to see if the fan kicked on and it did not. I looked for the wire to try and jump start the fan to see if it works at all, but it looks like the fan connection ends are somewhere under tank. Anyway I can test the fan from the other end of the connection? (Not sure if I am asking correctly, as in the cable that it connects to.)


Cause I was hoping I wouldn't have to syphon out my gas, remove tank, disassemble hoses, etc, just to test the fan :/.

[johnny]

http://www.motobrick.com/index.php?topic=5045.0

[Arredondo1]

 Thanks Johnny I tried all the suggestions in that thread just now and none of them turned the fan on. Seems that those methods rely on the connectons with the relays being in good working order. Might not be the case with this bike.


Really wanted to ride tonight but looks like Im gonna have to remove the tank to get to that hidden fan connection. :'(, hopefully the fan motor still works.

[Laitch]

Thanks Johnny I tried all the suggestions in that thread just now and none of them turned the fan on. Seems that those methods rely on the connectons with the relays being in good working order.

Maybe the fan is siezed. Do the blades rotate easily?

[Arredondo1]

Yes it spins easily.


 I have another problem now though, i lifted the tank too forcefully and the hose in the center came with it, what does it connect to?



Back to the fan, i can see all the wires now and it looks like this is the fan connection, can someone verify?



I could be wrong but it looks like the fan motor has two connections, the pic above being the 2nd.


And this being the 1st, i could be wrong, its just really hard to see in there.



Update: I was wrong its not one of the connections that is visible right away after you lift the tank, those go to the dash or controls couldn't tug on them at first cause they are zip tied pretty good. Its definitely the wire in the last pic. I just cant see where it leads after it comes up over that plastic piece. Theres a lot of sharing of connectors going on in that whole area, hope its not one of those.
Hmmm.... :falldown:

Who would of thought just trying to test the fan would take up so much time haha

[Laitch]

i lifted the tank too forcefully and the hose in the center came with it, what does it connect to?

There are usually two hoses emerging from beneath the right side of the fuel tank. The one with the valve that's in your photo connects to a pipe on top of the crankcase. It was designed to route fuel tank vapor to the crankcase but sometimes didn't work well as designed. Often the pipe on the crankcase will have been plugged and the valved hose rerouted from the tank to extend behind the right foot peg. The hose to the rear of the valved hose drains moisture that has accumulated around the fuel tank cap.

The hose in your photo is referred to as the "forward hose" in this document that describes a method of eliminating both those hoses from the tank.

[Arredondo1]

Thanks Laitch, I found the rubber hose that it leads to, definitely flimsy, looks like I'll be rerouting it as well.

[rbm]

You will normally find the fan connector fixed to the fan housing in an integrated clamp.  You would have to remove the radiator to access the connector.


Maybe you should measure the resistance of the motor.  To do that, use an ohmmeter on a low resistance range, probing between Pin A2 on the temperature relay socket (Purple/Yellow) and frame ground, with the temperature relay removed from its socket.  If you read a value around 100-400 ohms, then there is continuity through the motor windings and you will have confirmed that the wiring between the relay and fan is complete, that the motor connector is securely in place, and the motor windings are not burnt out.  If you read Infinity, then you have a fan motor problem and/or a wiring problem.  Either will necessitate dismantling the radiator to investigate.


If the motor appears to be good, then test it by applying +12V to Pin A2.  The fan should spin up.

[Arredondo1]

I got tired of measuring this and that, so went ahead and cut the ends that are visible from the intake side and jumped it from the battery.


It works.  :riding:


For now I think I will wire a toggle switch in. I'll tackle the relays not working another weekend . Anyone have a diagram for a toggle switch that wont drain the battery? I live across from an Autozone, light up switch is $3.


Update: This is how i wired it.
It wont drain the battery overnight will it?

[Arredondo1]

Now I have another problem....

I put the bike back together and now it wont start. Thought that maybe i did drain the battery somehow. So i placed the brand new battery out of my other bike. And still nothing, even with the switch wires disconnected it still wont start.


When does the fuel pump activate? Because I am not hearing it.

[rbm]

Fuel pump should activate as soon as you press the start button and the engine cranks.  What colour of wires did you slice and redo exactly?

[Arredondo1]

I cut the wires directly from the fan motor, nothing else. And then ran those to the battery to test the fan. After I confirmed that the fan works. I bought the switch and wired it up the  way the diagram above shows.

I really hope i didnt accidentally pull the fuel sender connections too hard when i was moving the tank back and forth to get under it.

I checked the fuses also and all were good.

Update: im checking the fuel sender connections now. Already looks bad...le sigh..


How do I test the sender connection to see if its getting power?


Murphys law seems to be in full effect on me with this bike...

[Laitch]

I put the bike back together and now it wont start. Thought that maybe i did drain the battery somehow. So i placed the brand new battery out of my other bike. And still nothing, even with the switch wires disconnected it still wont start.

Be sure your electronic fuel injection control unit under the seat is tightly plugged. Then check your 4-pin connection under the right side of the tank. Take it apart, clean it then connect it tightly. Take a second look at the fuse sockets to verify that they are clean.

[Arredondo1]

Ok Im about to go back out there and check those out. Gonna run to the store and buy some fuses to replace them all. I went ahead and connected the green and brown wires from the sender to the battery. And i heard a little buzz both times come from within the tank. I honestly dont know if that was the pump activating because Im not used to the sound yet, I only ran the bike a few times since I got it. And I dont have a reference since the k75 has a super loud aftermarket pump.


At the connection from the bike I get a power reading at the white cable but not the green cable. With or without ignition.


Update: Thanks Laitch, one of those suggestions did the trick. Swapped all new fuses,cleaned the fuse connectors, removed connectors to fuel injection ecu, cleaned them then made sure it was sitting right. Went through the relay box and did the same. It fired up again. So something was definitely loose, or a fuse wasnt connected right. Thanks for the help.


Now back to the relay for the fan....haha..really gonna just wait for the weekend.

[Arredondo1]

Ok so I rode the bike earlier today and it died on me at 2 stop signs. So I drove it home, went inside to get the multimeter. Bike would not start back up. Battery was at 12.7. So swapped battery with brand new battery that I have in the k75 and again it didnt start up.

Took the battery to get charged and in the meantime I pulled out the pump to test it. Pump works and I can now verify that the sound I heard when i jumped the fuel sender connection was indeed the fuel pump engaging. So all the wiring from the gas tank is good.

That now leaves the connection to the bike as the main culprit. Im 100% sure I yanked it to hard when I pulled the tank off. Becuase I nforgot to disconnect it first. when i went back tightening everything Im sure it was just barely making enough contact to run one last time.

How do I go about replacing this connector? The connection feeds into a loom, so im not sure where it goes. To a fuse? Relay? Does it merge with other wire I would like to replace the whole thing if possible.

Oh and heres a video of me troubles lol

[rbm]

From the sounds in the video, I'd venture to guess that you don't have power getting to the fuel pump or there is a problem with the connection to the ICU (under the tank near the headstock).  I don't hear the pump run on for 1.5 seconds following your release of the starter button.  The way to isolate whether it is the pump or the ICU:
1. disconnect the tank connector
2. at the harness side of the connector, connect up a voltmeter between Green/White (+ve) and Brown (-ve) wires.  Set the meter on a range that is capable of reading 12V DC.
3. Turn on ignition.  Voltmeter should read 0V
4. Press starter button.  Voltmeter should read 10V - 11V
5. Release starter button.  Voltmeter should jump to 12.7V for 1.5 seconds, then go to 0V


If it does this:  Problem is with the pump and/or tank wiring
If it does not do this:  Problem is with the ICU plug or HES

[The Mighty Gryphon]

It is possible the problem is in the connection of the wire to the terminal in the connector.  This will prevent power from appearing on the terminal.  I had this  same quitting problem with my K100RS and it was intermittent as well.    In my case it was the brown ground wire where the problem was.

[Arredondo1]

RBM, I did test the connection from the bike/harness and I did not have any current. Read zero with ignition set to on and stayed at zero when i pushed the power button.


Gryphon, how did you fix the wire? Did you replace the connector or rerun a new wire?

[rbm]

Ok, so the problem appears to be further up the food chain.  Something wrong with Fuse #6 or the FI relay, maybe the ICU or HES.


1. Put the voltmeter on the input side of Fuse #6 (Green/Red), negative lead to ground and turn on ignition.  You should read 0V
2. Press the starter button. You should read 10V -11V.


If yes, then there's a problem with Fuse #6
If No, then look further up the food chain


Pull the FI relay
1. Check for +12V between the Red wire of the FI relay socket and ground.  It should not matter whether the ignition is on or off.
2. Move the voltmeter positive probe to Green/Yellow on the FI relay. Leave the negative lead on ground.
3. Turn on ignition.  You should read +12V
4. Put the voltmeter positive probe on Green/Yellow and negative probe on Yellow/Violet on the FI relay with the ignition on.  You should read 0V
5. Press the starter button.  The voltage should go to +12V.
6. Release the starter button.  The voltage should drop to 0V after 1.5 seconds.


If you don't get this behaviour, the problem is further up the food chain, with the ICU.

[Arredondo1]

RBM, I can start checking those things tomorrow. But I really think the problem is here with this connection.





When i lifted the tank the first time, I forgot to disconnect it. I ended up pulling it really hard. I would like to replace not only the connector but the wires as well, since I think it may have gotten pulled from the other end as well. I dont think they are making proper contact. Therefore no power to the pump.

[The Mighty Gryphon]

On my connector, the continuity of the wire to the pin in the connector was intermittent and affected by wiggling the wire where it entered the connector.

I had to replace the connector from the wiring harness(the one on the tank was still good).   Fortunately, I was able to use a connector from an old wiring harness that I had bought with an engine.  If I am not mistaken, the connectors for the ABS system are the same as the tank.   I soldered it in and insulated with shrink tubing.  It looks like it was done at the factory.

If you don't have a used connector you can get a 4 pin SAE connector at almost any auto parts place.

[Martin]

If you are going to replace the four pin connector, pay a bit extra and get a fully sealed water proof one. Jaycar stock them, if you do it, it should outlast you.
Regards Martin.