mrkartoom Posted August 3, 2009 Report Share Posted August 3, 2009 (edited) I'm thinking I may have a problem with my radiator fan and wondering if anyone can verify my testing procedure. I noticed it hasn't kicked on since I got the bike put back together. Actually the bike is new to me and I'm not sure it worked before. It's been hot here and I have been plonking around in the back yard with it, so I'd think it would have come one. I assumed I either have a bad temp switch or the fan is bad, so I started testing by starting the bike and shorting the leads (2 blue wires) from the temp switch, but the fan didn't start up. Next I wired the fan directly to 12vdc and it ran fine, so I know the fan is good. I see the blue leads from the temp switch run into a black box (12v adjuster), which I assume senses the short from the temp switch and then powers the fan by switching ground or voltage or both. I now assume I either have a bad wire connection or this 12v adjuster box is bad. Am I on the right track here? Any other tests I should be doing to isolate the problem? Thanks for any info. Edited August 3, 2009 by mrkartoom Quote Link to comment Share on other sites More sharing options...
shercoman2k8 Posted August 4, 2009 Report Share Posted August 4, 2009 (edited) I had the same problem on my sherco... check your wiring, have you got a spare connector? If so, try switching the feed to the fan from whatever it's plugged into, into the spare. It turns out mine had been wired from the headlight spare cable and left the correct fan connector dangling around! Edited August 4, 2009 by shercoman2k8 Quote Link to comment Share on other sites More sharing options...
mrkartoom Posted August 4, 2009 Author Report Share Posted August 4, 2009 I had the same problem on my sherco... check your wiring, have you got a spare connector? If so, try switching the feed to the fan from whatever it's plugged into, into the spare. It turns out mine had been wired from the headlight spare cable and left the correct fan connector dangling around!Thanks for the tip. I wish it was something that simple, but mine is wired straight to the regulator. All the lighting bits and wiring were gone from the bike when I got it. Not sure why everyone in the US strips the lighting off or if it comes over here that way, but it seems pretty common.I think I have it isolated to a bad regulator. I ran the bike today and measured the voltage going to the fan from the regulator. My voltmeter sees 20-25vdc depending on rpms. That seems way too high. It stays at 20-25vdc with or without the closed contacts coming from the temperature switch, so I'm thinking its toasted. I assume the voltage is too high for the fan motor to work or else it would be running all the time. Doesn't seem to have cooked the fan so I'm lucky there. Going to order a new regulator. Did I mention what a PITA this bike is to work on? I had to drain the coolant, remove the header, and remove the radiator four times today to do my testing. Whoever stuffed all the wiring bits up into that little cavity in the frame is one cruel and heartless dude! Quote Link to comment Share on other sites More sharing options...
mrkartoom Posted August 5, 2009 Author Report Share Posted August 5, 2009 I did a diode test yesterday on the reg/rec "box" and it seems to have passed. Measuring between each DC output and both AC inputs I get open or .5v between all of them, depending on forward or reverse bias. I also confirmed that without the simulated closure from the temp switch everything read open. I'm thinking my "box" is fine and it must be something else. So far I've proven the regulator/rectifier tests good, the fan is good, the temp switch is good, and all the wiring tests out. All that leaves is the stator coil. Anyone know how to check it? I thought these things primarily failed on the ignition. I am reading .7ohms between the yellow wire and the frame. Not sure yet if that is a good reading or it should be open. Anyone know? Quote Link to comment Share on other sites More sharing options...
mrkartoom Posted August 8, 2009 Author Report Share Posted August 8, 2009 My fan is fixed. Turned out to be the regulator. Every component tested good on the bench or on the bike, so I decided to take some advice and try the regulator. I was told that 99% of the time if the temp switch is good then it's the regulator, so I got a new one. Even though it tested with identical results to the new one on the bench it was bad. 1 Quote Link to comment Share on other sites More sharing options...
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