coxy Posted December 16, 2012 Report Share Posted December 16, 2012 Hi Went out to a trial today and after about 15 mins of riding i noticed that the bike was overheating. At first i though it was the thermo-switch in the top of the radiator so tried by-passing this by connecting a small wire between the thermo wire (not the one going to the earth) and a live wire used for the wiring (have i by-passed the thermo correctly?) and nothing happened the fan didnt come in or anything. Got the bike home and took the bike to bits, connected the fan connector upto a 12v dc supply and it spun up no problems. Does anyone have any other ideas of what could be causing the fan not to cut in and out? Cheers Quote Link to comment Share on other sites More sharing options...
zerorev3rev4 Posted December 16, 2012 Report Share Posted December 16, 2012 you should have connected the 2 wires to thermo together Quote Link to comment Share on other sites More sharing options...
pete_scorpa3 Posted December 16, 2012 Report Share Posted December 16, 2012 Check the radiator pressure cap is working. Loss of pressure allows the coolant to boil at a lower temperature. Quote Link to comment Share on other sites More sharing options...
coxy Posted December 16, 2012 Author Report Share Posted December 16, 2012 How would connecting the two thermo wires together help as it would just short circuit back to earth then wouldnt it? I will give it a try though and see if it works tomorrow. How do you check if the radiator pressure cap is working? Cheers Quote Link to comment Share on other sites More sharing options...
zerorev3rev4 Posted December 16, 2012 Report Share Posted December 16, 2012 the thermo is a switch it can only work by connecting the 2 wires going to it when it reaches a certain temperature ,this can be earth /negative or live/ positive switching so the fan must have constant live ,and negative switching from the thermo seems quite straight forward Quote Link to comment Share on other sites More sharing options...
feetupfun Posted December 17, 2012 Report Share Posted December 17, 2012 Check the cap by squeezing a hose when the motor is up to temperature. Quote Link to comment Share on other sites More sharing options...
coxy Posted December 17, 2012 Author Report Share Posted December 17, 2012 Ok thanks guys will try again tonight and see how it goes. Quote Link to comment Share on other sites More sharing options...
sting32 Posted December 17, 2012 Report Share Posted December 17, 2012 Hi Went out to a trial today and after about 15 mins of riding i noticed that the bike was overheating. At first i though it was the thermo-switch in the top of the radiator so tried by-passing this by connecting a small wire between the thermo wire (not the one going to the earth) and a live wire used for the wiring (have i by-passed the thermo correctly?) and nothing happened the fan didnt come in or anything. Got the bike home and took the bike to bits, connected the fan connector upto a 12v dc supply and it spun up no problems. Does anyone have any other ideas of what could be causing the fan not to cut in and out? Cheers Thermo switches go bad, nothing lasts forever. I believe the 06 thermoswitch is located on top and inside the radiator. You have to test that you have "power" before you do anything else. Take the 2 wires that are headed to thermostat, where it plugs into the wires to thermostat, make something that will short those to wires together, but DONT LET that touch anything else. start bike, the fan should come on, if it doesnt you have voltage problem, wich is that black box (usually)... it could be you have lost a ground wire as well. If the fan comes on when the switch is "manually connected" then the thermoswitch is bad. what you can do is test it, if you have an "ohm meter" or a "multimeter" that can test for conductivity. the switch is what it says, a switch that activates when things get hot enough, it is just an "automatic" toggle switch, that completes the circuit to ground, by letting the 2 wires that go to it, touch together... This is why we short with a jumper the 2 wires to test that fan works. you can put thermostat in hot water, add heat, and a thermometer, and check continuity as water gets hot. supposed to come on something like 170-190 degrees (exact I cannot recall, but within 10% of 180 I think). Quote Link to comment Share on other sites More sharing options...
coxy Posted December 17, 2012 Author Report Share Posted December 17, 2012 Many thanks for the replies people. Tested the thermostat with the correct method tonight of joining the two wires. Started the bike up briefly and the fan spun up straight away. Looks like its the thermo thats gone so took the old one out and ordered a new one. I now know how to bypass the thermo properly incase i need to do it again in the future. Cheers 1 Quote Link to comment Share on other sites More sharing options...
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