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Cooling fan cut-in/cut-out

2709 Views 15 Replies 12 Participants Last post by mad, Jan 15, 2007

Jimbo

Discussion Starter · Feb 5, 2006

Hi all.
I'm finally getting around to fiddle with the bike for the first time this winter. I'm going to attempt a valve ajust., change the clutch and a few other small things.

So far the with guidance of the shop manual, I'm okay. But there is one question that it left unanswered. At what temp does the cooling fan kick in/out. I did a good strech of riding thru last summer (some in some pretty high temps) and the thing never came on once. I was also curious as to where the sensor was located. I did take a look this afternoon, but couldn't find any sign of one.

Thanks.
Jimbo

1 - 16 of 16 Posts

Stick

· #2 · Feb 5, 2006

Fill us in on what year/model ST you own. I have a 1998 ST2 that's been pretty bullet-proof so far (about 25K miles), an I think my fan comes on at about 220 F. I think it goes off around 210 F. But this is the wrong time of year to ask me...

Mine has 2 temp sensors. One for the dash readout, which I can unplug thru the left air conveyer (vent) on the fairing. Not sure where the other is located, but I'm pretty sure it's the input to the ECM.

Jimbo

Discussion Starter · #3 · Feb 5, 2006

Stick said:
Fill us in on what year/model ST you own. I have a 1998 ST2 that's been pretty bullet-proof so far (about 25K miles), an I think my fan comes on at about 220 F. I think it goes off around 210 F.
<location of sensors noted>

It's a '99 ST2 with 30k miles on it. The same applies for it being "bullet proof" 'cept for the clutch which I attribute to my own fault. It takes a bit of getting used to hyd. clutches after riding HDs for 30 years.

BTW, would you be the same Stick that's in RMH?

Thanks for the info.
Jimbo
#63

allikanbe

· #4 · Feb 5, 2006

I think my 05 ST4s fan comes on at 212 or 215 deg F. It comes on at stops in traffic. I don't think I hear or feel it turn off because I'm usually moving when that happens.

greggkirby

· #5 · Feb 5, 2006

Manual fan switch

Jimbo, I'm not sure @ what temp. my fan came on on my ST4s. I had DesmoTimes put a manual swith on my bike & I turn it on when the water temp. goes above 170 degrees. Even on the hottest days the coolant temp. will rarely go above 200 degrees. I like it. Gregg

Jimbo

Discussion Starter · #6 · Feb 6, 2006

greggkirby said:
I had DesmoTimes put a manual swith on my bike & I turn it on when the water temp. goes above 170 degrees. Even on the hottest days the coolant temp. will rarely go above 200 degrees. I like it. Gregg

I never thought about doing that, but now that you mention it and seeing the bike is half apart I'll be adding a switch to jumper the sensor.

Thanks.
Jimbo

Stick

· #7 · Feb 7, 2006

I'm Stick from PRM (People's Republic of Mass). I live in Central Mass. Grew up in NW CT.

Stef

· #8 · Feb 7, 2006

I've observed that my fan goes on at 200 deg on my 02 ST2.

FatguyRacer

· #9 · Jan 8, 2007

Thread Revival!!!

I was riding on Saturday in the 70+ degree heat we were having on the East coast. While doing stop and go traffic thru historic Annapolis on the way to a meetup my coolant temp was hitting 248. It never went above 248, but it was flashing at me when it was reading it. Once out of town the temps stayed down, but anytime i hit slow traffic the temps would climb back up.

Has anyone else seen temp readings this high. I'm thinking my fans arent kicking in, but then again maybe they are. The temp never went past 248 and the red check engine light never came on. There was no visable signs of overheating and i'm running straight water as far as i know. (my coolant reservior is clear)

Thanks

bevel450

· #10 · Jan 8, 2007 (Edited)

Well....there are at least two of us in the club. According to the guage I am overheating on a regular basis at 248F when I am in summer or stop and go traffic. I've checked the system for air voids and proven the operation of the fans in coming on at the correct temperature. No changes, so I bought a new thermostat which I will install the next time I have the fairings off.

( Interesting to me is that the dealers say they don't have a diagnostic procedure for the thermostat. Just like in your car it seems to be a replace-on-suspicion item.)

In certain conditions it is enough to have me thinking heart attack, but so far, nothing has broken and with the cold morning air that I ride in, I won't have a problem. But come spring, or any city riding ( yuk!) I need to replace that thermostat. If that doesn't do it then I will certainly go with LT's higher flow fan, and a manual switch. Certainly it pisses me off that I need to do this, but with my riding habits which are to get the hell out of town ASAP, it is not yet a critical issue with me. And I really love this bike.

Has anyone else experienced this situation ?

FatguyRacer said:
Thread Revival!!!

I was riding on Saturday in the 70+ degree heat we were having on the East coast. While doing stop and go traffic thru historic Annapolis on the way to a meetup my coolant temp was hitting 248. It never went above 248, but it was flashing at me when it was reading it. Once out of town the temps stayed down, but anytime i hit slow traffic the temps would climb back up.

Has anyone else seen temp readings this high. I'm thinking my fans arent kicking in, but then again maybe they are. The temp never went past 248 and the red check engine light never came on. There was no visable signs of overheating and i'm running straight water as far as i know. (my coolant reservior is clear)

Thanks

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860GT

· #11 · Jan 8, 2007

Mine got that hot last summer a couple of times. Didn't seem to harm it. It was 100 degrees or so outside. I think the heat harmed me more than the bike.

rickmillertx

· #12 · Jan 8, 2007

Mine (06 ST3s) comes on at 215 like clock work. Temp with fan running has never exceeded 225 even during 100 degree stop and go traffic. Unfortunately my blood was boiling at 214.

billhpowell

· #13 · Jan 11, 2007

How about 238 degrees

My fan doesn't click on till 238 degrees. The bike has two temp sensors, one on the front cylinder, and one on the back. One feeds the ECU to control the fan, the other the temp gauge. Figuring one or the other was off, I swapped the wires from one to the other on the sensor side. What do you know, the fan came on when the gauge read 238! Both sensors are equal. I quit farting around with it and turn on my fan switch at 200.

mad

· #14 · Jan 11, 2007

FatguyRacer said:
Thread Revival!!!

I was riding on Saturday in the 70+ degree heat we were having on the East coast. While doing stop and go traffic thru historic Annapolis on the way to a meetup my coolant temp was hitting 248. It never went above 248, but it was flashing at me when it was reading it. Once out of town the temps stayed down, but anytime i hit slow traffic the temps would climb back up.

Has anyone else seen temp readings this high. I'm thinking my fans arent kicking in, but then again maybe they are. The temp never went past 248 and the red check engine light never came on. There was no visable signs of overheating and i'm running straight water as far as i know. (my coolant reservior is clear)

Thanks

I'd REALLY recommend a cooling fan upgrade with manual switch from desmotimes. My temps never exceed 200 any more as long as I turn it on by 190 or so. It's a no brainer $100 upgrade to prolong the life of your bike if you ask me. Before the upgrade, my fan kept the temps below 222 ish after kicking on around 218 or so.

honest-al

· #15 · Jan 15, 2007

FatguyRacer said:
Thread Revival!!!

I was riding on Saturday in the 70+ degree heat we were having on the East coast. While doing stop and go traffic thru historic Annapolis on the way to a meetup my coolant temp was hitting 248. It never went above 248, but it was flashing at me when it was reading it. Once out of town the temps stayed down, but anytime i hit slow traffic the temps would climb back up.

Has anyone else seen temp readings this high. I'm thinking my fans arent kicking in, but then again maybe they are. The temp never went past 248 and the red check engine light never came on. There was no visable signs of overheating and i'm running straight water as far as i know. (my coolant reservior is clear)

Thanks

My 2002 ST-4 is suppose to cut in at 105c and one day it reaced 119!!!! I found a relay under the seat on the left side (what a STUPID place) and replaced it and now it works fine. I would like to have a manual swich but my wires are not the color of the ones showen before in a thread on this matter. Does anyone knoe the wire to come off of on a 2002 ST-4?

mad

· #16 · Jan 15, 2007

honest-al said:
My 2002 ST-4 is suppose to cut in at 105c and one day it reaced 119!!!! I found a relay under the seat on the left side (what a STUPID place) and replaced it and now it works fine. I would like to have a manual swich but my wires are not the color of the ones showen before in a thread on this matter. Does anyone knoe the wire to come off of on a 2002 ST-4?

My '02 ST4s has a blue and a black wire coming off the fan. The manual switch is tapped off of the blue wire.

1 - 16 of 16 Posts

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