Fan not running

[yoda]

My wife and I just got back from a 10 day run, and put 2600 miles on the bikes. I noticed several days ago, a gurgling from behind the right side cover, after we stopped. I had topped off the coolant reservoir before we left as it was low. I figured it was just because I had the notorious loose clamps and o-ring. I got some coolant, but was noticing that the fan was not coming on. Definitely a concern, as the temps were upper 90's plus, and there were several times we were sitting in traffic. I shut the bike off when I could, and over the past 800 miles, needed to add about a quart of coolant. I never saw it leaking/dripping, so my assumption is that without the fan coming on, it is cooking out the overflow in a way I am not seeing it. But to go through a quart, I would think I would see some evidence of it.
So what is the best way to start checking for why the fan isn't coming on? I did check the fuse, and it is fine.

[cajun2wheels]

Here is a previous discussion with many suggestions.
http://www.vulcanbagger.com/phpBB3/v...=23220&start=0

[AlabamaNomadRider]

Check the fuse, check the electrical connections.

[ringadingh]

Keep your eye on the fluid level for the next while. If it keeps going down slowly, it may be leaking so slow that you don't see it drip to the ground anywhere. Its usually the hoses between the cylinders that start to leak slowly, you may see some dry residue there from a leak.

[cnc]

I don't know how common this is on the Nomad but if you absolutely can not find any evidence of external leaking and you keep having to add antifreeze, then you may have an internal leak into the combustion chamber or oil passages at the head gasket. Look for a bit of white steamy exhaust and/ or a bit of dried crude on the exhaust tips, or milky looking oil.

[ringadingh]

That would be the worst case scenario Norm. Ive never heard of the Vulcan motors with head gasket problems, so they must be rare. The tubes though that go into the cylinder heads have been known to have the O ring allow coolant to seep by, but it usually evaporates before it can be seen on the ground. Sometimes the hoses around the thermostat housing work loose at the gear clamps as well.

[cnc]

I thought it was probably rare Steve, but just thought I would point it out.
I would imagine a quart in 2,600 miles will leave some tell tail crystallized crude where it is leaking and evaporating, maybe even a slight sweet smell when the bike is hot.

[yoda]

Thanks for the replies. I already checked the hoses and fixed the leaks there last fall, including replacing an o ring. The fan fuse is fine, so the next step is to see if it is the fan or the switch/connections. My assumption is that the bike gets hot in traffic since the fan doesn't come on, and boils the reservoir and pushing it out the overflow. The weird thing is, I am very in tune with coolant smells and I haven't noticed that or any fluid/ powder residue. The oil was just changed before the trip and that still seems fine, no anomalies on that end. It just sucked that I discovered it 1000 miles awayfrom home on the hottest weekend in Illionois this summer! LOL! I made it home, checking the level, and shutting the bike off when stopped in traffic. Hopefully it will be a simple fix. (although simple and cheap rarely go together for me...)

[AlabamaNomadRider]

If the fuse has been ruled out I would then check the connections and trace the wiring to make sure it isn't shorted out at some point.

[cnc]

Originally Posted by yoda

Thanks for the replies. I already checked the hoses and fixed the leaks there last fall, including replacing an o ring. The fan fuse is fine, so the next step is to see if it is the fan or the switch/connections. My assumption is that the bike gets hot in traffic since the fan doesn't come on, and boils the reservoir and pushing it out the overflow. The weird thing is, I am very in tune with coolant smells and I haven't noticed that or any fluid/ powder residue. The oil was just changed before the trip and that still seems fine, no anomalies on that end. It just sucked that I discovered it 1000 miles awayfrom home on the hottest weekend in Illionois this summer! LOL! I made it home, checking the level, and shutting the bike off when stopped in traffic. Hopefully it will be a simple fix. (although simple and cheap rarely go together for me...)

When it gets real hot have you seen the temp light come on? according to the manual it should come on at 235-243F and off at 226F. Boil over for a 50/50 coolant mix with a 15lb radiator cap is in the range of 260F.

[wiz]

I was staging for a parade last year (The Wolly Worm Festival in Beattyville, KY) and a friend behind me pointed out that my bike was taking a leak. It was pissing out coolant from the overflow and the fan wasn't running. I shut it down and checked the fan fuse. It was good. I let it cool down a bit then fired it back up for the parade (you can't miss a parade) and the fan was running again and I have not had the problem since. I suspect corrosion on the fan fuse and later I cleaned the fuse socket and fuse blades. I put it down as a fluke event with lots of hot miles since then with no problems. I did a coolant change later with Kawasaki coolant.

[waterman]

Originally Posted by Wiz

my bike was taking a leak. It was pissing out coolant from the overflow

First time I have heard of a Nomad marking its territory.

I think that everyone has covered most of the potential issues. Just take a good hard look around the engine and see if you see any residue.

[macmac]

First test for the fan is to pull the radiator connection, and short the 2 teminals on the connector. One side is supposed to be live at all times. The other side is the 12 + lead to the fan. A paper clip will work, and jumper lead is better.

If the fan works that brass switch is dead.

If the fan does not work you either have a bad fan, or bad wiring to the fan.

The next test is with a ice pick test light in the same connector. One side should be live.

If no side is live you have a wiring problem between the connector and the fuse box. Use the light to test the correct fuse.

No light and a good fuse, the problem is between the battery and the fuse box.

[yoda]

Well Mac, thanks for the concise plan of attack. I jumped the terminals and sure enough, the fan came on. What a pain to get to the stinking thing though! So I guess my only question at this point is, what is the chance I get a new switch, and it turns out to be something like the temp sensor instead? If the temp sensor wasn't reading correctly, logic dictates that the switch wouldn't trigger the fan. And that would explain why the temp light never came on.
Or am I missing something in the reasoning?
Well, maybe not. I just looked up the part on the fiche lookup, and it appears the fan switch and sensor are one assembly, with the warning lamp switch on a different circuit.
And of course the fan switch isn't a cheapie either...

[cnc]

Originally Posted by yoda

Well Mac, thanks for the concise plan of attack. I jumped the terminals and sure enough, the fan came on. What a pain to get to the stinking thing though! So I guess my only question at this point is, what is the chance I get a new switch, and it turns out to be something like the temp sensor instead? If the temp sensor wasn't reading correctly, logic dictates that the switch wouldn't trigger the fan. And that would explain why the temp light never came on.
Or am I missing something in the reasoning?

I think if you follow the wiring diagram you will see that the temp light sensor and the fan switch are separate and are not inter-connected. Only the fan switch controls the fan.