• Can't post after logging to the forum for the first time... Try Again - If you can't post in the forum, sign out of both the membership site and the forum and log in again. Make sure your COG membership is active and your browser allow cookies. If you still can't post, contact the COG IT guy at IT@Concours.org.
  • IF YOU GET 404 ERROR: This may be due to using a link in a post from prior to the web migration. Content was brought over from the old forum as is, but the links may be in error. If the link contains "cog-online.org" it is an old link and will not work.

Coolant temp fan switch (oops, moderator please move to C10 main forum)

B

bobct

Member
Member
Had my switch go bad, was stuck in traffic and had the temp gage going up near the red zone before I could pull over safely and shut her down. Fan wasn't running, puked a little coolant from the recovery bottle, maybe an ounce or two.
Let the bike cool down for a half an hour, traffic cleared up so I finished the last 5 miles of my commute home at normal speed and with temp gage at or below half.

Got home and found the two wires attached to the fan switch on the radiator, through the large vent on the left mid fairing. Got a short piece of wire and shorted out the switch, fan kicked on, so bad switch.

Since Napa is close by to me, I picked the Echlin FS130 switch from the Concours spare part listing.
Pulled fairing and got her installed pretty quick without any incidents.
Fired bike up and let her idle for 10 minutes or so, waiting for temp gage to go up to around halfway to make sure fan kicks on, another 5 minutes, temp gage is less than 1/4" off of that small area on the left part of the gage, cold section?. Anyways she doesn't want to go any higher, I checked the radiator after replacing the switch with the old plug the hole with your finger after old switch removal, then install new switch, so I don't think the coolant is low. Finally killed the engine and the fan was running!
So now I have a switch that kicks fan on just off the cold zone, I guess my chances of overheating are slim to none. Thoughts about having the fan running more?
Just wanted to let everyone know about the lower temp kick on point of the Echlin switch, I think they spec it out at @191-198 on, @182-189F off.
 
Rode to work this morning, 60F ambient air temperature. 25 miles 20% backroads and 80% slab, no traffic congestion. Temp gage barely got off the Cold area of gage so fan hasn't come on yet.
 
Temp gage sensor lives up in the thermostat housing, and senses temperature of coolant on the exit side of the thermostat, sending that signal to the dshboard temp gage...
The fan switch, which is a thermal switch  on/off control, senses coolant temp down in the radiator..
If during the minor incident, you lost enough coolant to make the level in the thermo housing lower han the thermostat valve, there would be air in there, preventing an accurate reading to your gage..
Make sure you top the radiator up fully, and then attache a hose to that bleeder nipple on the thermo housing, route that hose back into the radiator filler neck, and start the bike... when the temp raises, and the thermo opens, it will force the air trapped there, along with some coolant, back thru that bleeder hose, and into the radiator, purging the system.. have the radiator cap handy, as at that point, you need to close the bleeder, and slap the radiator cap back on fairly quickly, to prevent it burbling up and out of the filler...
 
Hey MOB great point on the temps being different from the gage sender to the fan switch. I will check that shortly and report back.
 
Bob,

I have the Advance Auto version TFS500? part # I believe, and also noticed the fan now kicks on at a lower temp. The stock fan switch, the needle around 12 o'clock, dead center. W/aftermarket switch (on my 2nd or 3rd over the last ten years), fan kicks on at about 2/3rds into the operating range.
 
Today I took tank off, attached a clear tube to thermostat housing bleeder with the other end in radiator filler neck. Started her up, opened the thermostat housing bleeder and coolant came out, no bubbles even after thermostat opened.
Opened up the bleeder on the water pump, all looked good there too.
I just have a fan switch that turns on at a lower temp. With the stock switch when it worked it would start the fan when the temp needle was near 12 noon, now the fan comes on when the needle comes up to about 1/3 of the way to red, not too much further past what I call is the warm up double line area of the temp gage.
I will keep an eye on it and figure if I should seek a replacement. Worse case it will run the fan when in town.
 
Sounds like everything is fine Bob, fan works, engine is safe, go ride and enjoy....
:motonoises: :motonoises: :great:
 
You must log in or register to reply here.
Top