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Could really use a copy of the 2004 Magnum 330 service manual. trying to figure out my cooling fan not working and its been a bear!! Thank you!!

ben.wittman@hartfiel.com
Sending you the manual, but's whats so difficult about the fan? 3 parts; fan motor, thermistor and controller

Put 12v on the fan motor wires - fan runs = motor good
Connect the two yellow/black wires at the thermistor - fan runs and hot light come on = controller working - replace thermistor - fan and hot light do not turn on - replace controller
 
Could really use a copy of the 2004 Magnum 330 service manual. trying to figure out my cooling fan not working and its been a bear!! Thank you!!

ben.wittman@hartfiel.com
Got it
Sending you the manual, but's whats so difficult about the fan? 3 parts; fan motor, thermistor and controller

Put 12v on the fan motor wires - fan runs = motor good
Connect the two yellow/black wires at the thermistor - fan runs and hot light come on = controller working - replace thermistor - fan and hot light do not turn on - replace controller
If I unplug the thermister I get constant fan and Hot light. So that makes me assume the Thermister and Fan are good. (I replaced the thermistor anyway as I wasn't sure if it was giving the correct resistance. it was cheap). So you are saying it has to be the ECM?? What is the Thermistor Jumper for? Could that be the culprit? I havent been able to find much information on it. (#15 in the picture and not used on the 2003's I believe, only the 2004's)

141707
 
If you unplug the thermistor the fan comes on? Are we working on the same year and model 04 330 Magnum?

The fan is not supposed to come on unless the thermistor leads are shorted together and the jumper device it to turn the fan on without turning on the hot lamp - it's more or less to verify the calibration of the thermistor.

141710
 
The manual you sent lists the Ohms for the jumper at 18.2 KOHM. I'll check that. Otherwise it must be the ECM... Which sucks because they are spendy $$$
Spendy? Would you feel better if it was no longer available and the vehicle was unrepairable? If it were my machine and I intended to keep it more than a couple of years, I'd buy the ECM now and have it available. When it is NLA from Polaris, it will be worth whatever someone is willing to pay for it on Ebay.
 
Actually, I believe the creating the short process is for the older models. The manual you sent me even shows that unplugging should turn the fan and light on on page 10.21.
141742


And I understand your point on my expensive comment. Yes, it is good they are still supporting some of the parts. If it did get to the point of parts not being available I'd probably end up controlling the fan manually with a toggle switch. My comment was more of just expressing the frustration that it had to be one of the more expensive parts of the oil cooling system.My luck I guess!!

Thanks again for the help!
 
As I've said many times - service manuals contain lots of errors - as you can see by the chart, decreasing resistance turns the fan and light on - just unplugging the thermistor creates infinite resistance - if the fan does not run with the thermistor unplugged, try shorting the leads together - either way either the thermistor or the control is the faulty part - the test just confirms which one is the problem.

If you unplug it and the fan runs replace the thermistor - if you unplug it and short the leads and the fan runs, replace the thermistor - if the fan dos not come on either unplugged or shorted, replace the control module or make it a manual control.

Simple test and simple fix
 
How common is it for the thermister to be bad? the fan ran with the thermister unplugged. Then I replaced the thermister with a new one and it still runs when unplugged. I have not tested the resistance on the thermister yet, but is a failure out of the box common??
 
If its supposed to make the fan run when unplugged, then it is probably working - you will need to operate the quad to get the oil temp hot (260 degrees F)enough to turn the fan on - might be hard to do - I had to race my 97 XR250 Honda on a 80 degree day for about an hour to get the oil over 280 degrees and the hottest I ever got the oil was 300 degrees, but it's the reason I switched to synthetic oil - mineral oil starts to break down at about 300* while the synthetic I selected had a breakdown temp of about 350*. If you are using the recommended synthetic oil, whether the fan runs or not should not be an issue unless you are getting the oil temp to around 300*

Faulty out of the box thermistor is rather uncommon, but not out of the failure cannot be ruled out - easy to test - connect multimeter to the terminals and read the resistance as the sensor is heated suspended in a pan of water on the stove or other heat source. I use a pot pie pan and a propane torch in my shop.
 
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