Cooling fan control issue...
Thread Starter
Melting Slicks
Joined: May 2007
Posts: 2,171
Likes: 1
From: Warwick RI
Cooling fan control issue...
I was going to go back to ECM control so that is why I started looking closer at this but my mind is officially blown now...
I cut the wire from the ECM to my fan relays, wired in my own adjustable switch set at 190 to kick the taurus fan on high.
So all should be good right??
Now check this out, I notice my temp was rising while driving (my shroud was too restrictive but fixed that) I stop and 30 seconds later...fan comes on again.
Here is what is stumping me...
If I cut the wire from the ECM and put my own switch to ground, how the &$%# is the fan shutting down when rolling (>12MPH) and starting 30 seconds after I stop just like the the ECM fan operation described in the FSM...I cut the wire
I didn't see anything that interupts power to the relay in the wiring diagrams.
I think that the point is moot now that I have opened up my shroud to allow good air flow at speed but I just can't figure it out and it is driving me nuts
I cut the wire from the ECM to my fan relays, wired in my own adjustable switch set at 190 to kick the taurus fan on high.
So all should be good right??
Now check this out, I notice my temp was rising while driving (my shroud was too restrictive but fixed that) I stop and 30 seconds later...fan comes on again.
Here is what is stumping me...
If I cut the wire from the ECM and put my own switch to ground, how the &$%# is the fan shutting down when rolling (>12MPH) and starting 30 seconds after I stop just like the the ECM fan operation described in the FSM...I cut the wire
I didn't see anything that interupts power to the relay in the wiring diagrams.I think that the point is moot now that I have opened up my shroud to allow good air flow at speed but I just can't figure it out and it is driving me nuts
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
I was going to go back to ECM control so that is why I started looking closer at this but my mind is officially blown now...
I cut the wire from the ECM to my fan relays, wired in my own adjustable switch set at 190 to kick the taurus fan on high.
So all should be good right??
Now check this out, I notice my temp was rising while driving (my shroud was too restrictive but fixed that) I stop and 30 seconds later...fan comes on again.
Here is what is stumping me...
If I cut the wire from the ECM and put my own switch to ground, how the &$%# is the fan shutting down when rolling (>12MPH) and starting 30 seconds after I stop just like the the ECM fan operation described in the FSM...I cut the wire I didn't see anything that interupts power to the relay in the wiring diagrams.
I think that the point is moot now that I have opened up my shroud to allow good air flow at speed but I just can't figure it out and it is driving me nuts
I cut the wire from the ECM to my fan relays, wired in my own adjustable switch set at 190 to kick the taurus fan on high.
So all should be good right??
Now check this out, I notice my temp was rising while driving (my shroud was too restrictive but fixed that) I stop and 30 seconds later...fan comes on again.
Here is what is stumping me...
If I cut the wire from the ECM and put my own switch to ground, how the &$%# is the fan shutting down when rolling (>12MPH) and starting 30 seconds after I stop just like the the ECM fan operation described in the FSM...I cut the wire
I didn't see anything that interupts power to the relay in the wiring diagrams.I think that the point is moot now that I have opened up my shroud to allow good air flow at speed but I just can't figure it out and it is driving me nuts
What did you ground your adj "switch" to?
Got a diagram of the sender setup and wiring for the adjustable switch you used?
Last edited by engle1147; Dec 15, 2008 at 10:22 PM. Reason: diagram please
Thread Starter
Melting Slicks
Joined: May 2007
Posts: 2,171
Likes: 1
From: Warwick RI
It is the Flex-o-lite switch with the radiator bulb
Any guess? I am floored by this one
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Last edited by engle1147; Dec 15, 2008 at 11:08 PM.
Thread Starter
Melting Slicks
Joined: May 2007
Posts: 2,171
Likes: 1
From: Warwick RI
If the circuit is that simple sounds like a bad switch/radiator bulb...or your coolant level is too low and the coolant is not hitting the sender when the engine is reved up....maybe test (like how you can test boil a thermostat on the stove to see if and when it opens) the switch by boiling the sender part of the switch while attaching an ohm meter accross the adjustable switch's contacts and see what it is really doing.
I am going to go to an internal switch so it will take that out of the equation
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Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
bin=bin file, or type such as $8d to understand what tables you have to work with in the software. Based on your first coment of them shutting down at a certain mph, in constants and scalers (tuning software) you will have 2tables, (fan 1 and 2) " fans dis-able vehicle speed". Is it possible these became changed ?,
Thread Starter
Melting Slicks
Joined: May 2007
Posts: 2,171
Likes: 1
From: Warwick RI
bin=bin file, or type such as $8d to understand what tables you have to work with in the software. Based on your first coment of them shutting down at a certain mph, in constants and scalers (tuning software) you will have 2tables, (fan 1 and 2) " fans dis-able vehicle speed". Is it possible these became changed ?,
Programming change ... no
What is stumping me is the fact that I CUT the ecm ground at the relay and the fan still shut down and started again.
Drifting
Joined: Feb 2008
Posts: 1,537
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From: NE Ohio
2024 C4 of the Year Finalist - Unmodified
Are you sure you cut at the right relay? Do you have two fans? Some have 2, a pusher and a puller. The pusher is between the bumper and the radiator, the puller is between the engine and radiator.
When you turn on the switch you just installed the fan should turn on as long as the key is on.
Thread Starter
Melting Slicks
Joined: May 2007
Posts: 2,171
Likes: 1
From: Warwick RI
Are you sure you cut at the right relay? Do you have two fans? Some have 2, a pusher and a puller. The pusher is between the bumper and the radiator, the puller is between the engine and radiator.
When you turn on the switch you just installed the fan should turn on as long as the key is on.
When you turn on the switch you just installed the fan should turn on as long as the key is on.
I appreciate the basic approach because you never know when something is over-looked or you are dealing with a noobie. I have two relays (primary and secondary) and were using both at one time for the dual speed operation on the taurus fan so neither is connected to the ECM.
I just threw this up here because I wanted to see if anyone could explain why the fan seemed spooked. I think that engle had the best idea in that I am using a bulb type switch and while rolling the sender temp is dropping down.
Drifting
Joined: Feb 2008
Posts: 1,537
Likes: 177
From: NE Ohio
2024 C4 of the Year Finalist - Unmodified
I appreciate the basic approach because you never know when something is over-looked or you are dealing with a noobie. I have two relays (primary and secondary) and were using both at one time for the dual speed operation on the taurus fan so neither is connected to the ECM.
I just threw this up here because I wanted to see if anyone could explain why the fan seemed spooked. I think that engle had the best idea in that I am using a bulb type switch and while rolling the sender temp is dropping down.
Last edited by kenmohr; Dec 17, 2008 at 09:50 AM.
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
If you indeed cut the right wires to remove ECM control and you are using stock relays then there are two possibilities:
-the fans have internal switches
-the manual switch or relay is defective
-the fans have internal switches
-the manual switch or relay is defective
Team Owner
Joined: Mar 2001
Posts: 54,124
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From: Cincinnati, Oh USA
You don't provide very good info for anyone to provide any help, but here is my take. You installed a thermostatic switch (adjustable switch by your terms) that turns on a 190 F. When you are moving, your coolant temp drops and your fans shut off because your thermo switch shuts off (temp lower than 190). When you stop, coolant temp goes above 190 and your thermo switch turns on and the fan runs. What is so hard to understand about that?
Drifting
Joined: Feb 2008
Posts: 1,537
Likes: 177
From: NE Ohio
2024 C4 of the Year Finalist - Unmodified
You don't provide very good info for anyone to provide any help, but here is my take. You installed a thermostatic switch (adjustable switch by your terms) that turns on a 190 F. When you are moving, your coolant temp drops and your fans shut off because your thermo switch shuts off (temp lower than 190). When you stop, coolant temp goes above 190 and your thermo switch turns on and the fan runs. What is so hard to understand about that?
Thread Starter
Melting Slicks
Joined: May 2007
Posts: 2,171
Likes: 1
From: Warwick RI
You don't provide very good info for anyone to provide any help, but here is my take. You installed a thermostatic switch (adjustable switch by your terms) that turns on a 190 F. When you are moving, your coolant temp drops and your fans shut off because your thermo switch shuts off (temp lower than 190). When you stop, coolant temp goes above 190 and your thermo switch turns on and the fan runs. What is so hard to understand about that?
I do not appreciate the condescending tone of this post. I did not need help, I am quite capable of resolving my own issues. I posted this to give some senior members something to ponder. I thought that it would be obvious that the coolant temp was not going below the shut off. The fact that the ECM wire to each relay was cut and yet it seemed to still be shutting the fan down was intriguing.
Mods...this thread can be closed if you like, it has out-lived it's usefullness
Drifting
Joined: Feb 2008
Posts: 1,537
Likes: 177
From: NE Ohio
2024 C4 of the Year Finalist - Unmodified
Don't know what wire you cut but the they were not from the Ecm or it couldn’t control the fans. People are trying to help you and there is no need for you to be offended or offensive.