Cooling fan problems - Honda RC51 Forum : RC51 Motorcycle Forums
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 19 (permalink) Old 05-10-2013, 01:21 PM Thread Starter
Lifetime Premium
 
James_03_rc's Avatar
 
Join Date: Sep 2010
Location: Newport NC
Posts: 2,697
Mentioned: 5 Post(s)
Quoted: 80 Post(s)
Cooling fan problems

Heres a new one for you

My cooling fans were turning on at 228F and turning off at 220F. Ive read through the service manual, nothing like this is out lined in there.
-No FI light
-Everything works and runs like it should
-I can turn them on and off with my manual switch mod.
-SP2
-Engine Ice, less than 1000 miles old, 23k on the clock

I started the bike about an hour later and let it reach temp, this time on at 219 and off at 211. Guess the problem fixed itself.

Anyone have an idea what the issue may have been? The main reason I started this thread is that Im not sure that if its a precursor to a future problem or not. If so, I want to take care of it now, before its a bigger problem. But Im guessing that water got somewhere it wasn't supposed to. I'm about to check: for water; the grounds; wires for wear; and over all condition of everything. I'll update with what I find.

Thanks for any insight,
James
James_03_rc is offline  
Sponsored Links
Advertisement
 
post #2 of 19 (permalink) Old 05-10-2013, 05:58 PM
Member
 
Join Date: Apr 2013
Location: Huntington beach ca
Posts: 75
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Open up wsm. Go to wiring section. For cooling fans check all your powers grounds. If you can take the farings off and run it hot. See if it acts up. If it does do a wiggle test with the connectors that pertain to the cooling fans sensors ect.. It's probley a bad sensor in the tstat housing .
Radrc51 is offline  
post #3 of 19 (permalink) Old 05-10-2013, 06:32 PM
Moderator
 
SubSailor's Avatar
 
Join Date: Oct 2008
Location: Sarasota, FL
Posts: 6,468
Mentioned: 24 Post(s)
Quoted: 89 Post(s)
My initial suspicion was the ECT sensor starting to fail.
SubSailor is offline  
 
post #4 of 19 (permalink) Old 05-10-2013, 07:53 PM Thread Starter
Lifetime Premium
 
James_03_rc's Avatar
 
Join Date: Sep 2010
Location: Newport NC
Posts: 2,697
Mentioned: 5 Post(s)
Quoted: 80 Post(s)
I found water on the ECU connectors. I'm going to pull them off make sure they're clean and put some dielectric grease in the plugs.

I don't feel that it's a ground issue. My fan switch is wired in to ground the low amp side of the fan relay.

Once I get the time, I'll dig into it deap enough to check out and the ECT.



Sent from Motorcycle.com App
James_03_rc is offline  
post #5 of 19 (permalink) Old 05-10-2013, 11:17 PM
Lifetime Premium
 
madbuyer's Avatar
 
Join Date: Sep 2010
Location: Indy
Posts: 8,335
Mentioned: 17 Post(s)
Quoted: 226 Post(s)
Quote:
Originally Posted by James_03_rc View Post
I found water on the ECU connectors. I'm going to pull them off make sure they're clean and put some dielectric grease in the plugs.
Talk like that gives Sub a chubby....



The very first schoolbook that was written had God all over it. --Dave Mustaine
madbuyer is offline  
post #6 of 19 (permalink) Old 05-10-2013, 11:22 PM
Moderator
 
SubSailor's Avatar
 
Join Date: Oct 2008
Location: Sarasota, FL
Posts: 6,468
Mentioned: 24 Post(s)
Quoted: 89 Post(s)
Quote:
Originally Posted by madbuyer View Post
Talk like that gives Sub a chubby....
Grease for peace man.
SubSailor is offline  
post #7 of 19 (permalink) Old 05-10-2013, 11:29 PM
Moderator
 
SubSailor's Avatar
 
Join Date: Oct 2008
Location: Sarasota, FL
Posts: 6,468
Mentioned: 24 Post(s)
Quoted: 89 Post(s)
Quote:
Originally Posted by James_03_rc View Post
I found water on the ECU connectors. I'm going to pull them off make sure they're clean and put some dielectric grease in the plugs.

I don't feel that it's a ground issue. My fan switch is wired in to ground the low amp side of the fan relay.

Once I get the time, I'll dig into it deap enough to check out and the ECT.



Sent from Motorcycle.com App
According to the manual on P.19-2, at 176 deg F, the ECT resistance should be 310-326 ohms.
And at 230 deg F, the resistance should be 139.9-143.5 ohms.
As you can see, the higher the temperature, the lower the resistance of the ECT.

Hypothetically, corrosion or tarnish on the ECT contacts would tend to add resistance to the ECT resistance value, making the ECU believe the temperature is lower then actual.
SubSailor is offline  
post #8 of 19 (permalink) Old 05-11-2013, 03:36 PM Thread Starter
Lifetime Premium
 
James_03_rc's Avatar
 
Join Date: Sep 2010
Location: Newport NC
Posts: 2,697
Mentioned: 5 Post(s)
Quoted: 80 Post(s)
Quote:
Originally Posted by madbuyer View Post
Talk like that gives Sub a chubby....
When the man is right, he's right.
I worked as a mechanic on AAV's (Google image "AAVP7A1") for 6 years, with them sitting for half their life and in saltwater for the other half, you lean fast that those damn things won't run long with out it.




Quote:
Originally Posted by SubSailor View Post
According to the manual on P.19-2, at 176 deg F, the ECT resistance should be 310-326 ohms.
And at 230 deg F, the resistance should be 139.9-143.5 ohms.
As you can see, the higher the temperature, the lower the resistance of the ECT.

Hypothetically, corrosion or tarnish on the ECT contacts would tend to add resistance to the ECT resistance value, making the ECU believe the temperature is lower then actual.
Sub, I always enjoy reading your posts, always very informative.
Thanks man.

Pulled my ECU, found some light corrosion on a few of the pins. Cleaned them off, problem still exists. On at 219 off 211

Wouldn't extra resistance from corrosion or tarnish also throw off the temperature display too?

Well...Time to pull the air box and all that mess to get to the ECT. Then figure out a way to test the resistance at 230 I wonder if my stove can push water that far past boiling.

James

Sent from Motorcycle.com App
James_03_rc is offline  
post #9 of 19 (permalink) Old 05-11-2013, 11:53 PM
Moderator
 
SubSailor's Avatar
 
Join Date: Oct 2008
Location: Sarasota, FL
Posts: 6,468
Mentioned: 24 Post(s)
Quoted: 89 Post(s)
Quote:
Originally Posted by James_03_rc View Post
When the man is right, he's right.
I worked as a mechanic on AAV's (Google image "AAVP7A1") for 6 years, with them sitting for half their life and in saltwater for the other half, you lean fast that those damn things won't run long with out it.






Sub, I always enjoy reading your posts, always very informative.
Thanks man.

Pulled my ECU, found some light corrosion on a few of the pins. Cleaned them off, problem still exists. On at 219 off 211

Wouldn't extra resistance from corrosion or tarnish also throw off the temperature display too?

Well...Time to pull the air box and all that mess to get to the ECT. Then figure out a way to test the resistance at 230 I wonder if my stove can push water that far past boiling.

James

Sent from Motorcycle.com App
Since the ECT gives the ECU the input of coolant temperature based on variable resistance, any change in resistance will alter the perceived coolant temp, and what is displayed by the ECU (which controls the instrument display).
There is the possibility that the ECT itself may be failing internally.
So if all your contacts are clean and you're still getting faulty readings or fan operation, then it might be the ECT itself. Nothing lasts forever.

The thing is, your ECU is going by what the ECT is sending, despite what the actual coolant temp is.
But your numbers are close to what the manual says.
For the SP1, Fan On is at 208-216 F, and Fan Off is at 199-207.
I'm sure the SP2 follows similar temps, though not stated.

For my SP2, it's been Fan On at 218 F, and Fan Off at 205-210 F.
Yours is Fan On at 219 F, Fan Off at 211 F.
I'm wondering if 1 deg F difference for both is ok and not worth the effort.

Last edited by SubSailor; 05-12-2013 at 12:55 AM.
SubSailor is offline  
post #10 of 19 (permalink) Old 05-12-2013, 12:31 AM
Lifetime Premium
 
madbuyer's Avatar
 
Join Date: Sep 2010
Location: Indy
Posts: 8,335
Mentioned: 17 Post(s)
Quoted: 226 Post(s)
James...as you are completing this work, how about some pictures if possible. If indeed the sensor has failed, I for one would like to see it.



The very first schoolbook that was written had God all over it. --Dave Mustaine
madbuyer is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Honda RC51 Forum : RC51 Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome