Rad Fan Quit
 

I don't have the time to search this topic. I'm sure there are threads on this one, but please help me out. I am about to go on vacation and will need the bike when I come back.

My rad fan refused to come on by it's self Thursday coming home from work.
I just finished testing the fan. It does work.
I am in the process of hooking up a swithc to go manual.

Why do the not get a signal to turn on????

What part should I be looking at?


Thanks

Maybe the weather isn't hot enough for the fan to need to come on....

BBC Weather | Toronto

je ne comprends pas.

You had time to write your post out, and test the fan but not the time to do a click and type in search??

How did you test the fan? One of the wires attaches to a temp switch on your radiator. Take that wire off and touch it to metal on the radiator. It should turn on. If not, your radiator isn't grounded properly.

If it does, then my next guess would be to make sure your system is full of coolant. If there is air in it, it will not circulate properly and so the "hot" coolant won't be getting to your fan switch. Or if there is an air pocket at the fan switch, it definitely won't turn on. Check the radiator cap too.

Good luck!

Yes, that's what I was thinking.
But in hot weather the fan comes on at 104 or less.
The temp guage showed 118 and it had not come on yet?????

I took the fan out and hooked it up to an alternate battery sourse and it ran fine.
I am in the middle of rigging up a manual switch.
I will hook up the switch and still see if the fan kicks in before 120.
I think thats as high as I want to let it get before I switch it manually.


I just checked, there is plenty of fluid in the bottle. Didn't take off the rad cap.

My bet is on the temp switch. I just replaced one in a friends cruiser for this very reason. Compared part numbers and it is the same as the Superhawk's. And many other Hondas.

I wouldn't disable the failsafe. Rigging a manual switch is a dangerous game to play. It only takes one time forgetting to really mess up your motor, plus turning it on and off all the time gets very tedious (I speak from experience). You can order a new temp switch if you want, but again test the fan against the radiator.

The temp switch is set to cool the bike down until about 100. 120 is way too hot.

Where is the temp. switch?

Screwed into the lower portion of the right side radiator. The manual gives instruction to test it

I thought was the temp. sensor?

Temp sensor is in the thermostat (located in the frame in between your carbs on the left side of the bike). It sends a signal to your ECU and gauges.

The temp switch is screwed into your radiator, and it's only purpose is to switch the fan on. It doesn't send a signal to anything, just completes the circuit that turns on your fan when the water reaches a certain temp (in the case of our bikes, 100c).

the switch is on the right side rad,on the opposite side if the water neck.
you will see a black wire,that is a ground wire,do not hook positive to it.

it has to be one of 3 problems

rad cap
thermostat
fan switch

these are gonna be the most likely,i was having same problem,but mine was a thermostat.
another member was having the same problem,but it was the rad cap,not holding enough pressure i guess.
the switch is a possibility.
cheap easy and the first i would go with is the rad cap.
fan will come on late or never if its one of these problems.if im wrong,others will chime in and get it straight. good luck

I can't remember how many Honda car cooling fan temp switches I replaced (or instructed students to replace) in 34 years of teaching vocational automotives, but it was more than a few.

But ground the switch wire to the engine or a frame bolt to test, since the radiator is painted, and therefore insulated. Use a jumper wire in one of the terminals. When jumped to ground, one of the 2 terminals should turn the fan on. If not, check for voltage to one of those terminals. If voltage is there, the fan motor is bad, or there is a broken wire or bad connection. If no voltage, check the fuse.

Its not the radiator cap. That would make it run hot but not affect the fan which would run its ass off. Its the fan switch.

I cant believe you took the fan out! Thats why you had no time to search, you spent all day doing that (you coulda tested it in the bike with the method mentioned above).

You just need one of these VTR1000 Firestorm SC36E 97-05 Radiator Fan Switch 13622 | eBay

I wouldnt buy that one but look around. I have one thats the low temp one but I didnt like it, the fan ran constantly.

You checked the fuse already...right? :3

Oops oh yeah check the fuse

Ofcourse I checked the fuze. I checked that on the road side. As soon as I saw a high temp.

Spliced in a nice aux. switch. Will gef a new rad switch and leave the aux. Switch for good measure. Thanks guys.

Its been said but DONT count on just the switch for more time that is absolutely needed. I have both (manual and auto) but trust me it will only lead to great unhappiness if you rely on just the switch.

agreed, it's just temporary untill if get it figgered out.
I really had no time to order a part and wait for weeks for it to come in.
With only a few days left to ride to work, I wanted to get the fan running again so I don't lose the last nice days in November.
I will order a switch on the way home, taking careful note of the temp as I ride.
Switch should fix it, thanks to the help I recieved here.

Thanks guys.

Hey guys. I think it's the thermostat. Even with the fan on, the heat stayed about the same. Don't tbink the thermostat is opening.

Is it located under the rad cap?

A quick check to see if it could be the thermostat (before you tear it apart):

Open the radiator cap (if the bike is warm, do this very very slowly). Turn the bike on and let it warm up. The thermostat opens somewhere around 160 degrees F. So let your bike hit 170 or so. Then look at the water in the radiator through the cap. It should be flowing (where it was staying still before).

The actual location of the thermostat is inside your frame on the left side of the bike. You remove the housing by taking those two bolts off (coolant will come out, so drain it first). But you don't have to remove the housing from the bike, and if you're patient you can get the thermostat out through the side of the frame, so you don't have to take the gas tank and airbox off. The little piece inside is what may be giving you problems.

Again, may just want to blip the throttle and squeeze and smack all of the tubes with the handle of a screwdriver all to make sure there are no air pockets. A little air in the system will cause quite a bit of headache.

Attachment 25373

Btw your thermostat housing will be pointing forward, my setup is a little different. But the location is the same...

I havent run a thermostat at all in years. Hey fuzz, what temps are we talking about?

I just had a headache with cooling and posted all about it. (https://www.superhawkforum.com/forum...-issues-26889/)

It turned out to be the stupid (and obvious) radiator cap. For $10ish replace it. That could be all it is. it fixed my problem.

This bike shares a cap with millions of cars so read the thread. DO THIS FIRST, it could save you a world of trauma.

I saw 111 degrees this morning.

Will read thread tonite.

111 isnt that hot but here is the rad cap info; get one on the way home

If anyone reads this in the future just remember an autoparts store will have it as a stant(brand) 10233 or equivalent.
(ford escort 97-02,explorer 97-05,mustang 97-02,ranger 95-11 to name a few for cross ref)

Just tell them one of the vehicles in the list & they will have it. 5 min fix.

I think he's reading in Celsius... 111 is pretty hot.

Oh crap that stupid metric system has come back to haunt me! Why didnt I pay attention in 2nd grade.?

Right? Why would we base our scale to that of the rest of the world? ...taking the easy way out using water as a reference point.

I much prefer a scale based on brine and blood.

OK, picked up a rad cap. And nothing different.
Will be ordering a switch and a thermostat tomorrow.

I'm betting that your fan switch is OK... the reason that I say this is because having the fans on manual all the time would have solved the cooling issue (meaning, if it was broken, your bike wouldn't have reached 111). It is pretty unlikely that your fan switch and thermostat went out at the same time.

You can test your thermostat before ordering one (if it's worth the time for you). It's outlined in the manual, but in general, you remove it from the housing and put it in a pan of water and heat that pan up. Keep track of the temp, and when it reaches a certain temp... something like 70 c (don't remember the exact number, but it's in the manual), it will physically open up. What this does is allow the coolant to circle through the radiators once the motor heats up a bit.

You can also do what smokinjoe said and just remove the thermostat from the housing. The negative to this is that it may take longer for your bike to warm up, BUT if the bike then stays cool you know that the thermostat wasn't working properly. I'm just giving you some options do do while you wait for the parts or even troubleshoot more before you order stuff.

I'm thinking it's the switch.
I felt both rad hoses and they both seem to be very hot.
Rad fluid would not flow over to the second rad with the fan if the thermostat didn't work.

On the way home, I kept the temp below 101 all the way home in traffic.
The fan did lower the temp like expected.