| Author | Message | ||
     Seth |
This is an odd one... but possibly cool  I recently put a new set of T-Storm heads on my bike. As you all know the rear head has an engine temperature sensor (ET) stuck in it. My bike also has an S-3 cooling fan mounted to it. Now my question is if the ET can be used to trigger the S-3 cooling fan instead of the little silver guy that mounts via using the front cly. rockerbox cover mounting screws. | ||
| Buellistic |
Seth: IMHO it would not supply 12v to fan as the OEM fan wiring is ... Which is activated off thermostat switch that the instruction sheet says to put on front head ... One system uses the front head(fan) as a temperature referance and the rear head(ET sensor) for the other ??? The ET(engine temperature sensor) supplies a 0-5 volt signal like a 02 sensor ... "BUT" "i" suppose one could build a electronic switch that would work off the ET which should turn the fan on when the head reaches 180 degrees ... That would be between 0.81 Volts(638 ohms) and 0.62 volts(463 ohms) ... That would be a interesting project ??? In BUELLing LaFayette | ||
| Ratbuell |
You'd need a relay between the 5v sensor and the fan, since the sensor is only "switching" 5v on and off. Use the 5v to trigger the relay, opening/closing 12v to the fan as indicated by the sensor. Shouldn't be tough, just have to find out the true V sweep of the temp sensor. Also I'd hesitate to use the same sensor that sends signal to the ECM...there may be a resistance variable in there that although negligible on a meter may send the ECM into conniptions. | ||
| Seth |
After a week of searching and scratching my head, all it took was one quick post! You guys are the coolest! Thanks for the quick replies | ||
| Oldog |
Seth I would not recomend that unless your S3 is carbed the aft head TS is tied into the ECM altering the circuit will alter the temp Reading that the ECM is seeing stick with the original switch.. OOPS checked your profile the et can be used as your sled is not FI as Buellistic suggests some electronics are needed and a relay to cycle the fan on and off. (Message edited by oldog on October 09, 2007) | ||
| Bartimus |
From the Badweb archives: The BUELL S3/S3T COOLING FAN KIT PN Z0008.MA 99-02 should be still avalable ... Have a 1997S3T and the PARTS technican said it would not fit my 1997S3T, "i" can send you a PICTURE that it "WILL" ... The Z0008.KA is for the X1 99-02 is bacicly the same ... The FRAMES are the same where the FAN "FITS"/"MOUNTS" ... It is still on the www.buell.com site under M2,S3/S3T,and X1 accessries(details) ... In BUELLing LaFayette Here is a link for a Harley cooling fan: http://www.latus-harley-davidson.com/Fan-Kit-for-T ouring-Models-1.htm | ||
| Seth |
Thank you for the link but... ..."i" have an S-3 cooling fan already installed but the problem with it is since the temp. sensor mounts via the rockerbox cover screws, I can now no longer attach the sensor. I upgraded to the XB style one piece rockerbox covers and it'll no longer fit properly. I tried making little spacers and getting longer screws but the pricks kept leaking. Using the ET to trigger a relay seems like a great solution. | ||
| Mmmi_grad |
http://www.suburbanharley.com/catalog/productdetai ls.cfm?ProductID=2523 in case someone needs a fan | ||
| Oldog |
Ok My shot is start at radio shack get some bits you need to build a comparator circuit that takes the temp sensor on one side and a pot on the other, when the voltage from the sensor reaches a specific value the comparator flips on this triggers a transistor and that flips on a 12v dc relay whos contacts are rated for the fan load.  The sensor will not operate a relay directly It may work with a LARGE transistor this is my basic idea, look for a book by forest mims about operational amplifiers. IHTH |
