Cant get my radiator fan to work!!!

[cbrsmurf]

Ok, it was working find before I switched to water/waterwetter for 12/12 trackday. At the track, the fan never came on and I think the bike was overheating. I replaced it with coolant/water today, still no go!!

The fan isn't stuck, but decided to lube with a lil wd40 anyways.
I checked all the connections and reseated them, them seem ok.
The fuse is fine, too... I switched a fuse with my headlight fuse, not the fuse.
When the temp gets about halfway on the temp scale, the coolant starts to bubble... so that means the thermostat works too right? If I let it keep running, the coolant/radiator opening starts to steam and flow out of the radiator (if I leave the cap off).



What I don't understand is that it was working fine before I switched to water/waterwetter. Same thing happened last June for the Buttonwillow trackday. Didn't work for 3 weeks and then miraculously started to work again after I poked the fan with a stick (it tried it multiple times this time, but no worky). WTF??!?!:grr:

[dre_2k2_f4i]

I can't offer much advice above: use a volt meter to track down where the problem starts. I don't know if there's a way to "trick" your bike into tripping the fan sooner so you don't have to wait for your bike to get hot.

[tjb]

i had the same problem with my bike a while ago. Mine turned out to be the fuse, but if you check the connections like Dre suggested, and find that the electrical is working okay, you can connect a manaul switch to the fan. It may be a faulty switch on the fan that you can just bypass.

[cbrsmurf]

Originally posted by tjb
i had the same problem with my bike a while ago. Mine turned out to be the fuse, but if you check the connections like Dre suggested, and find that the electrical is working okay, you can connect a manaul switch to the fan. It may be a faulty switch on the fan that you can just bypass.


I don't know how to put a manual switch to the fan :(

I guess I need a multimeter? I'm thinking of just buying one since I think it will be a useful tool. How much do they go for? And what voltage is it supposed to read for the fan?

[cbrsmurf]

Is there any way to induce the fan to turn on by applying some kind of electrical discharge?

[CjrJAM]

Originally posted by cbrsmurf
I don't know how to put a manual switch to the fan :(

I guess I need a multimeter? I'm thinking of just buying one since I think it will be a useful tool. How much do they go for? And what voltage is it supposed to read for the fan?
You can borrow mine if you need it Jeff and the voltage should read 12V I believe...

[GPTECHMAN]

jEFF YOU DID GO DOWN, MAYBE A CONNECTION CAME LOOSE. DID YOU CHECK AT THE PLUGS? FUSES?

[tjb]

if you have a clymer, it will tell you exactly how to check it. It will tell you where to attach the leads of the volt/ohm meter, how to make the fan go on, all that stuff. If you don't have a clymer for an older bike, you should get one anyway! I know you are trying to sell it, but check ebay or something for a used cheap one.

[cbrsmurf]

Originally posted by GPTECHMAN
jEFF YOU DID GO DOWN, MAYBE A CONNECTION CAME LOOSE. DID YOU CHECK AT THE PLUGS? FUSES?

Well the thing is, it stopped working before I went down so I don't think that's the problem. Plus I checked all the connections I could easily get too.


I do have a Clymers' but I don't think it said anything about that. I'll dbl check again.


Hey Ceez, I would love to borrow it, but if it's cheap, I think it'd be more convenient for both of us for me to just buy my own. I'll have to check prices and get back at ya. Thanks yall.

[tjb]

for my bike, it is covered in the electrical section. it is under cooling system...don't know if it will be the same, but it might.

[CjrJAM]

Originally posted by cbrsmurf
Hey Ceez, I would love to borrow it, but if it's cheap, I think it'd be more convenient for both of us for me to just buy my own. I'll have to check prices and get back at ya. Thanks yall.
The prices vary anywhere from $10-$300 and than some, I have the higher end model made by Fluke. You are more than welcome to it anytime, as goes for all you other slugs also :-p

[cbrsmurf]

Ok, so one wire leading to the fan has voltage while the other one doesn't (or I can't) get a reading. THis is just with the bike on. I don't know if there's supposed to be voltage coming through when the heat reaches a certain point and turns the fan on??

So I've ruled out the thermosensor and thermo switch... it must be the fan or fan motor itself or the the connection to fan. How do I narrow down the problem further??



Oh, I figured out why I didn't get a reading on the multimeter the first couple of times. It was because the frame, brake lever, and kickstand all didn't provide sufficient grounding. Only one of the shinier bolts on the frame itself provided a good ground.

[tjb]

So, my 86 honda vfr is very similar to the older CBRs in a lot of ways, maybe this will help you. My Clymer says this under FAN Motor Switch Testing/replacement:

1. Remove the lower section of the front fairing as described...
2. Pull back the rubber boot and disconnect the electrical connector from the fan motor switch.
3. Place a jumper wire between the fan motor switch electrical connector and a good ground.
4. Turn the ignition swithc ON; teh cooling fan should start running
5A. If the fan does not run, either the fan or the wiring to the fan is faulty. Remove the jumper wire and perform the following:
a. turn the ignition OFF
b. disconnect gthe 2-pin black electrical connector from the cooling fan motor.
c. Connect a 0-20 DC voltmeter between the black/blue and green terminal on the wiring harness side of the conncetor (on my bike these are just the two wires going to the fan).
d. Turn the ignition switch ON. There should be battery voltage.
e. if there is no battery voltage, check for a loose electrical connection or break in the fan motor wire or a blown fuse in that circuit.
5B. If the fan now runs, the fan motor switch may be defective; test the fan motor swich as follows:

um...PM me if the fan runs and i'll loan you my Clymer...don't want to type the rest...hope that helps.

[cbrsmurf]

Originally posted by tjb
So, my 86 honda vfr is very similar to the older CBRs in a lot of ways, maybe this will help you. My Clymer says this under FAN Motor Switch Testing/replacement:

1. Remove the lower section of the front fairing as described...
2. Pull back the rubber boot and disconnect the electrical connector from the fan motor switch.
3. Place a jumper wire between the fan motor switch electrical connector and a good ground.
4. Turn the ignition swithc ON; teh cooling fan should start running
5A. If the fan does not run, either the fan or the wiring to the fan is faulty. Remove the jumper wire and perform the following:
a. turn the ignition OFF
b. disconnect gthe 2-pin black electrical connector from the cooling fan motor.
c. Connect a 0-20 DC voltmeter between the black/blue and green terminal on the wiring harness side of the conncetor (on my bike these are just the two wires going to the fan).
d. Turn the ignition switch ON. There should be battery voltage.
e. if there is no battery voltage, check for a loose electrical connection or break in the fan motor wire or a blown fuse in that circuit.
5B. If the fan now runs, the fan motor switch may be defective; test the fan motor swich as follows:

um...PM me if the fan runs and i'll loan you my Clymer...don't want to type the rest...hope that helps.

k, i'll give it a shot tomorrow, thanks tjb!