Radiator fan/relay questions - '90 XII

[Eydugstr]

Ran into a problem on my '90 XII, the radiator fan stopped coming on. The bike was parked and running on it's centerstand, when it began to heat up and push some antifreeze out of the overflow tube. I immediately turned the bike off and let it cool down.

After searching the forum I found a post where the fan could be tested on the bike, by disconnecting the switch at the bottom of the radiator and grounding the wire running to the fan. Can hear the relay click but the fan doesn't come on, so I'm assuming the motor is out. There seems to be a lot of used radiator motors available on ebay, so that's no big deal.

Is there anything else I should be looking out for? Should I test anything else? Granted I'm going to double check all the hoses, change the antifreeze, possibly the thermostat and radiator cap.

[Mr Jensee]

The fan isn't coming on, on the Charlie Voyager 1200. When I do the forks to replace the seals I need to hunt down the reason as well. I am interested in other responses on how hard it is to diagnose if the temp sensor and the fan are related and how hard is it to change out the sensor if that is the problem.

[Eydugstr]

If it's any help Mr Jensee here's a link to where I found Triton28's post about testing the radiator fan sensor - viewtopic.php?f=15&t=10996&p=80056&hili ... tor#p80056

[doug of so fla]

The main problem that has been with the fans not coming on.
The 1200 sensor goes bad at the bottom of the radiator . If you look at where it comes out of the radiator it makes a very sharp turn and the wires break right there, short out or corrode, whatever it is, testing the sensor will show not good. You can sometimes see the wires coming out of the insulation at the right angle turn.

If grounding out the wire on the frame runs the fan, then it is usually the sensor is bad.

[Eydugstr]

Tried grounding the wire running to the sensor, but the fan motor didn't come on. Could hear the relay clicking, though. Can the fan motor assembly be removed without removing the radiator?

[triton28]

The circuitry to the fan motor can be tested in place by uncoupling the black plastic 3 wire harness side/4 wire fan side connector from the fan motor and connecting a multi meter, set to DC 20 Volts, to each of the Blue and Black/yellow pins in the harness half of the connector.
Turn on the ignition switch and ground the Yellow pin of the 3 wire harness side connector and you should get battery voltage, which, if the battery is fully charged, will be 12.5-12.7 Volts. Turn off the ignition switch and the voltage should revert to 0 Volts.
Actually any voltage reading means the relay is working and power is being sent to the fan motor.
Be careful with the proximity of the test leads onto the pins as they can not touch since that would be a dead short! I used to usually depress the tab on the pins and remove them from the rear of the connector for clearance from each other. Then I decided to use a spare fan side connector with loose wire leads that I had cut off a dead fan motor to avoid the hassle of trying to get the multimeter pins to co-operate.
Since you have already tested the Yellow wire to ground, if you do the above test and get voltage then the motor is toast.
The radiator will have to be disconnected from the bottom large hose and the mounting bolts removed and then the radiator may have enough clearance from the frame tubes for the fan motor to come off. If not then the upper large and lower small bypass hoses will have to be disconnected as well and then remove the radiator.
As others have posted, if you have to go to this level it would be advised to replace the 4 manifold o-rings where the 4 pipes of the manifold enter the cylinder block. Be careful with removing the manifold bolt in front of cylinder #s 1/2 as it is under the manifold and any leakage will have worked in around the bolt threads and corroded the aluminium of the block onto the steel threads of the bolt. Fortunately the bolt in front of #s 3/4 is above the manifold and usually comes out easily.
I use a deWalt 18V cordless 1/4"mpact driver set to light impact and give the bolt a couple of very quick shots in the tighten direction to crack any corrosion and then reverse hammer it out. Upon reassembly I always use "never seez" on the bolts.
Hope this helps,
Dave

[VoyKimmer]

Just because the relay clicks doesn't mean the relay is good. The contacts inside powering the unit get pitted. Easy to swap relays. There all the same. Just swap plugs.

[Eydugstr]

TY for the responses everyone. Will try to test the voltage at the connector. Did test the ground wire going to the sensor and came up with 12.8 on a DC 20v setting on the multimeter, but didn't have the upper fairing off for access to the pigtail connector going to the fan. Have the entire fairing off now so will go ahead and test the connector and swap the relay and see what that does.

EDIT: Okay did the tests at the connector. Used a spare crimp connector, and using the side of the left front fork as a ground, plugged it into the yellow wire's female side and got 12.4v with the switch on, and 12.8 with the switch off. From what I've seen/read the rad fan is supposed to get power at all times from the battery, so I'm assuming that when the switch is turned on and the dash lights come on, that explains the .4 drop.

Got nothing on the black and yellow wire side, on or off, but on the blue wire side would get .20v with the switch on.

[triton28]

Yeah I forgot about the constant on power to the fan Yellow lead. But the Blue should show 12 Volts on the meter with one meter leg to ground, ( or the Black/Yellow ground wire), and the other meter leg to the Blue wire when you ground out the Yellow, not .20 Volts. Sounds as though what VoyKimmer mentioned may be the case; a bad relay.
As mentioned, swap the relay (Blue, 2 of White/Blue and a Yellow) wires to another relay, then recheck the voltage at the connector when grounding the Yellow and see if you get 12 Volts with a different relay. (Remember to map the wire colour/connection points of the relay you are going to use!)
If so, reconnect the black fan connector/wires and then ground out the Yellow wire down by the fan temperature switch and if the fan motor is good it should run since it now would be getting 12 Volts from a working relay when the Yellow is grounded out. If the fan motor still doesn't run with 12 Volts at the connector, then either the ground wire on the motor housing mount is bad/dirty/intermittent or the motor is indeed faulty.
If you still only get .20 Volts with the different relay there may be a partially broken Blue wire somewhere in the harness. To test for this possibility run a temporary jumper from the Green wire of the fan side of the connector to ground and a jumper from the battery positive to the Blue wire of the fan side of the connector. This is a direct 12 Volt unswitched/unrelayed/non harnessed circuit which will tell you if the motor, or it's grounding is good or not; it should run when you make the last connection so long as the motor and it's grounding is good. If it doesn't run with this temporary jumpering, then the motor or it's grounding is bad.
Once/if you get 12 Volts using the stock controls/wiring and the fan running when grounding the Yellow wire, then you can tell if the fan temperature switch itself is working as designed, or not, once the bike heats up with the Yellow wire connected to it.
Or, if you have the coolant drained, you can remove the switch and perform the suggested temperature resistance readings test in the Service Manual remembering to be gentle with the switch lead, as doug of so flo pointed out; they become brittle/crusty/corroded over time.
Electrical/switch problems are never any fun to work out.
I hope this helps in some small way and doesn't confuse the issue.

[Mr Jensee]

All this yellow black blue white is confusing. I am after all getting old. Couldn't you just run a set of wires from the positive and negative of the fan to the battery and it if comes on the fan is good? Then it would be a simple job to trace down the sensor wires to look for breaks. If none are found then logic tells me it has to be the sensor itself. Does that have to be ordered or can a substitute be located locally?

[VoyKimmer]

I agree mr Jensee. Keep it simple. That's why I suggested swapping relay connectors. So simple and will rule out the relay. I did have mine go bad a couple years ago. Could hear the click but no fan. Swapt connectotors from the acc relay and it worked. Later put in a new relay from Toyota $7.00

[Eydugstr]

Thanks again for everyone's responses - Sorry it took so long to respond but the bike decided to throw me a curve ball and wanted to take more time to troubleshoot it before I posted anything else. Turns out the wiring harness connector at the relay appears to have a short in it.

After I had taken apart the connector to the harness that ran down to the fan motor, cleaned up the terminals (a little) and re-connected it. For grins and giggles, tested the motor again by grounding the yellow wire running to the radiator switch...and for the first time since this all began, the fan motor comes on. Was stumped because I knew I hadn't done enough or found enough to make a real difference. So I tested the motor a few more times. It ran twice on two tries, then clicked at the relay on the third, then ran on the fourth, and on the fifth try didn't do anything!

So decided to swap relays and see what that did, as suggested. Relays looked in great shape, no corrosion at the connectors, all of them a nice gold or copper color. At first it didn't do anything, then it would click every once in a while, then do nothing, then ran, then clicked, then ran, then nothing...So a began moving the wires at the connector and finally began to get the fan motor to consistently come on or off depending on how I moved the wires near the base of the connector at the relay.

So my plan at this point is to replace the connector at the relay and go from there. I have a similar connector in a crimping kit, but it doesn't have the securing clip on the side. Does anyone know if the same connector with the clip is available? If the relays are that cheap and available will try to get one and throw it in the glove box as a spare.

[cranky]

...you really hafta find the problem... it can't be an "I think I got it"...

One of my favorite rides it 50 across Nevada, 100s of miles of pretty much
nothing.... sure you want to take that trip? Another is 6 from Tonopah, Nv
to Ely, Nv...... @180 miles with NOTHING along the road.... sure you wanna
try it?

Best to Ya on finding your confidence builder!!!!

[Eydugstr]

Agreed, Cranky...it's a "must be working 100%" moment. Haven't had the pleasure of traveling in the Southwest (yet) but intend to take this bike on a trip in July, and KS gets plenty hot.

Was able to re-use the original connector after a fair amount of work to remove the old terminals. After getting new terminals crimped on and re-inserted in the connector, tested the fan twenty times in a row grounding out the wire at the radiator switch. All twenty times the fan came on, not one dead moment or click from the relays. Will refill the bike with anti-freeze and then run it and make sure the fan is coming on properly.

Triton28 - Never did get the blue wire to test more than .20v, but will go through the testing procedures again before I button everything up. Thanks again.

Do have a couple more questions, though...First, has anyone on the forum used the aftermarket radiator fan switches (Caltric part # SR111) in place of the OE 27010-1180 ? The aftermarket ones are way more reasonable ($25 vs. $106) At $25 I don't mind being testing one out but wondered if anyone here had any experience with them.

My next question is why did Kawasaki run the wiring so close to the coolant bleeder bolt? Do you guys disconnect the wire running by it or just work around it?

[triton28]

Glad you got it solved.