Hi
I think I have a problem with my heat sensor.
Sometimes, my fan doesn't start and the red light light up. And other times, my fan just don't stop running even if the engine is stopped.

Is the heat sensor the problem ?
And where is it located ?
Is it expensive ?

THanks

 

The temp switch is is the 2 wire switch located on the top, right side of your engine in the housing where the short hose connects.
The fan will run after the engine is off as long as the engine is stopped by the kill switch on the left handle bar switch and the key is left on. If you turn the key off the fan should stop.
The 00 and 01 fans don't last nery long due to the way they are mounted, if you do a search you will find plenty of posts on this subject. The vibration breaks the wires inside. Connect your fan direct to a 12volt power source, if it does not come on then it has given up the ghost too. Hope this helps

 

The red light also comes on due to oil problems - if the red light is on, and the fan isn't running (assuming it still works) then you should look into an oil problem.

How long has it been doing this red light on with no fan blowing? Who did your last oil change? Have you ever rolled your ATV over (on it's back?)
When doing oil changes you have to be sure to do a couple of things: 1. drain the case 2. drain the oil tank 3. change the filter 4. clean the screen filter in the oil tank (Remove the hose coming off the bottom of it) 5. On year 2000 models you have to also bleed the oil circuit as described in the manual. (If you need more info on this process just say so.)

If you have rolled the machine onto it's back there is the possibility of an air bubble forming in an oil line (I don't know which one) and causing oil starvation. If this is a possibility you will want to bleed the oil circuit using the same process as when changing the oil - you pretty much do an oil change.

There are other potential problems that I have no clue about & possibly someone else could shed some more light on the situation for you.

 

Hi
I have done my oil change about 1 month ago. The light came ON even before than after the oil change.
It look like she only comes ON when it's very Hot.
I didn't roll over my DS.
I try the fan on 12 volts and it's working
What could be the problem ? Heat sensor ?

 

It would seem very likely that your heat sensor (AKA: Thermostat) has gone bad. On DS650s this is usually because something got jarred loose on the inside. On new DS650s (2003s I know for sure) they are applying a small amount of glue or silicon to the terminals so that they cannot move independantly thus making them more solid. So once you replace your thermostat, I sugest you add some silicon or glue to keep them from moving & breaking again.

 

Far be it from me to correct someone just for the sake of correction so to prevent a guy (Mobile1) from buying parts that he doesn't need, here goes.
There have been three different parts mentioned in this thread that are assumed to be the same part. Hopfully this will clarify.

Thermostat: round space saucer looking part that is consealed inside the thermostat housing, right side top of engine, not visable without disassembly. Its job is to keep the engine coolant temp around 180 deg. by controlling the flow of coolant through the radiator/engine

Temp. Sensor: Located in the thermostat housing, its only job is to turn the red light on when the engine coolant temp reaches ~240 deg.

Temp. Switch: This is also located in the thermostat housing and has two wires. This one turns the fan on when the engine coolant reaches ~210 deg.

Any one of the three could be the problem or it could easily be something else. Diagnosis through testing is the only way to to know for sure.

 

JSsDS did a great job clarifying the parts in question. I will add to the it for more confusion. [img]i/expressions/face-icon-small-wink.gif[/img] The fan will sometimes not run when the temp switch is calling for it when one of the wires inside that connects to one of the 4 magnets is busted if the fan happened to stop at that point. And sometimes it will still work. But not always. Meaning your fan is going bad. Usually it will run slower when this happens. But again, not always. You can determine this by giving the fan a spin when you know it should be working (the light is on) if it spins…there ya go. If not then prolly it’s the Fan switch. I wired in a toggle switch and put it on the dash. That way if my fan switch goes again (and it will, been through 3) I can turn the fan on manually. With that said I’ve also gone through 4 fans. This is one area I know all to well.
[img]i/expressions/face-icon-small-sad.gif[/img]

 

Larry,

To alleviate the fan problem I had a friend of mine fabricate & install some mounts for the fan just like the 2002 & newer ATVs on my 2001. Now my 2001 has it's fan mounted exactly the same as my 2003, so that should kill the problem with dead fans. Before you do the conversion, be sure to give yourself time since the radiator must come off. Also be sure to order the fan supports before begining your installation (about $2.50 each.)

I'm glad someone on here piped in with more info about the thermostat, switch & sensor since I've never had that problem I haven't taken the time to tear mine apart & learn the three.

 

Hey Chris...yea I though about that. What I did this last go around was put rubber spacer in between the frame and the fan where it bolts. So far so good. Going on 4 months now[img]i/expressions/face-icon-small-smile.gif[/img] (Knock on wood)
That will be the way I go if the fan give out again though. Thats the other reason for the switch. I can test the fan at any time. Also when I drag race a lot I just turn the switch on and leave it on. Cooler motor makes more HP right [img]i/expressions/face-icon-small-happy.gif[/img]

 

THanks gang
I'm pretty sure it's my temp switch that is not working ( the 2 wire sensor).
How do I test it ? Am I suppose to read 0 ohm if the engine is cold ?