Electric fan runs all the time

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steve2724

steve2724

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Hello
I have 70 dart with a 360 4 speed. I put a cold case Radiator in it last year.
It has a electric fan that runs all the time so the car barely gets above 145 degrees.
It has a Edelbrock duel plane 7576 intake on it. The one port for the antifreeze on intake it taken by the temp gauge.
I was wondering how you guys hook up your fan so it would come on at 180.
Thanks for your help.

977202CC-13F5-4A82-BA80-8D9690B95E35.jpeg
 
Yeah how is it staying at 145° if you have a thermostat?

The fan should be wired to a thermostatic switch at the very least, that way you’d have a a basic on/off at certain temperatures so you wouldn’t have to worry about manual control with a regular toggle switch.

This is a relay set up for a single 30 amp fan, not sure exactly what you have or what kind of amperage it pulls but this would be a super basic way to control the fan and pull the power so it’s not coming through the bulkhead connector.

Summit Racing SUM-890115 Summit Racing™ Electric Fan Thermostat Kits | Summit Racing

There’s other similar set ups with higher amp relays and different temperature switches are available for various on/off temperatures.

I use a Dakota Digital fan controller for my dual speed, dual electric fans but that’s a more complicated relay set up. The controller does have a lot of nice functions though, you can program and change the on/off temps for both fans and the high/low speed, change the run time after shut down etc…

Dakota Digital PAC-2800BT Dakota Digital Electronic Fan Controllers with Bluetooth | Summit Racing
 
I am thinking it doesn’t get hot because the fan runs all the time plus the cold case rad. It has a 180 thermostat. I don’t know
 
steve2724 said:
I am thinking it doesn’t get hot because the fan runs all the time plus the cold case rad. It has a 180 thermostat. I don’t know
Click to expand...

Yeah but if the thermostat is working properly then the radiator isn’t really even involved, it’s just circulating water in the engine.
 
72bluNblu said:
Yeah but if the thermostat is working properly then the radiator isn’t really even involved, it’s just circulating water in the engine.
Click to expand...
Maybe bad thermostat. I will check it out
 
How are you determining that it is running at 145?

Maybe it is running above the thermostat switch (assuming that is what I see on top of your manifold) set point and that's why it is running all the time?


Also how do you know it is running all the time. It might be unpowered at interstate speeds. Can you see it while driving? Can you measure the current draw of it when driving?


Just looked at your sender again.

That silver coiled part should go to the fan controller.


Also it looks like an old school bulb type in the manifold that controls a diaphram in the temperature controller

Screenshot_20221011-192248.png



Or is that the temp sender for a mechanical temp gauge?

Screenshot_20221011-193750.png
 
Last edited:
Dana67Dart said:
How are you determining that it is running at 145?

Maybe it is running above the thermostat switch (assuming that is what I see on top of your manifold) set point and that's why it is running all the time?


Also how do you know it is running all the time. It might be unpowered at interstate speeds. Can you see it while driving? Can you measure the current draw of it when driving?


Just looked at your sender again.

That silver coiled part should go to the fan controller.


Also it looks like an old school bulb type in the manifold that controls a diaphram in the temperature controller

View attachment 1715996926


Or is that the temp sender for a mechanical temp gauge?

View attachment 1715996934
Click to expand...
Yes I have a mechanical temp gauge.
 
Dana67Dart said:
How are you determining that it is running at 145?

Maybe it is running above the thermostat switch (assuming that is what I see on top of your manifold) set point and that's why it is running all the time?


Also how do you know it is running all the time. It might be unpowered at interstate speeds. Can you see it while driving? Can you measure the current draw of it when driving?


Just looked at your sender again.

That silver coiled part should go to the fan controller.


Also it looks like an old school bulb type in the manifold that controls a diaphram in the temperature controller

View attachment 1715996926


Or is that the temp sender for a mechanical temp gauge?

View attachment 1715996934
Click to expand...
Dana67 What are you running for temp sensor and gauge?
 
72bluNblu said:
Yeah how is it staying at 145° if you have a thermostat?

The fan should be wired to a thermostatic switch at the very least, that way you’d have a a basic on/off at certain temperatures so you wouldn’t have to worry about manual control with a regular toggle switch.

This is a relay set up for a single 30 amp fan, not sure exactly what you have or what kind of amperage it pulls but this would be a super basic way to control the fan and pull the power so it’s not coming through the bulkhead connector.

Summit Racing SUM-890115 Summit Racing™ Electric Fan Thermostat Kits | Summit Racing

There’s other similar set ups with higher amp relays and different temperature switches are available for various on/off temperatures.

I use a Dakota Digital fan controller for my dual speed, dual electric fans but that’s a more complicated relay set up. The controller does have a lot of nice functions though, you can program and change the on/off temps for both fans and the high/low speed, change the run time after shut down etc…

Dakota Digital PAC-2800BT Dakota Digital Electronic Fan Controllers with Bluetooth | Summit Racing
Click to expand...
Hey, did you by chance wire in an override switch to power the fan(s) manually instead of through the controller. I'm trying to wrap my mind around how that would be done using the Dakota fan controller. Seems like it would require a 5-pin relay upstream of the switched power for the controller? Do you know of anyone whose used one of those controllers with a manual override?
 
mopowers said:
Hey, did you by chance wire in an override switch to power the fan(s) manually instead of through the controller. I'm trying to wrap my mind around how that would be done using the Dakota fan controller. Seems like it would require a 5-pin relay upstream of the switched power for the controller? Do you know of anyone whose used one of those controllers with a manual override?
Click to expand...

I didn’t wire in an override switch, I just use the controller.

The controller already triggers a pair of 5 pin relays to run the fans, I would think you could run a switch off of one or both of those relays if you wanted.

I wired mine up using @goldduster318 ’s diagram
 

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72bluNblu said:
I didn’t wire in an override switch, I just use the controller.

The controller already triggers a pair of 5 pin relays to run the fans, I would think you could run a switch off of one or both of those relays if you wanted.

I wired mine up using @goldduster318 ’s diagram
Click to expand...

Thanks. I was looking at that diagram earlier today. Unfortunately, it's slightly different with a single 2-speed fan like I've got. I'll figure it out eventually. Thanks again.
 
72bluNblu said:
I didn’t wire in an override switch, I just use the controller.

The controller already triggers a pair of 5 pin relays to run the fans, I would think you could run a switch off of one or both of those relays if you wanted.

I wired mine up using @goldduster318 ’s diagram
Click to expand...
Quick question for those of you who run a Dakota Digital fan controller. If you disconnect the battery for whatever reason, do the settings for the controller need to be re-entered?
 
mopowers said:
Quick question for those of you who run a Dakota Digital fan controller. If you disconnect the battery for whatever reason, do the settings for the controller need to be re-entered?
Click to expand...
In my case no, all of my settings are saved when the battery is disconnected
 
mopowers said:
Quick question for those of you who run a Dakota Digital fan controller. If you disconnect the battery for whatever reason, do the settings for the controller need to be re-entered?
Click to expand...

devilchicken said:
In my case no, all of my settings are saved when the battery is disconnected
Click to expand...

I agree, it holds the settings with the battery disconnected.

I’m sure at some point if it sat long enough they might have to be re-entered, but I know I’ve left my battery switch off for days and even weeks at a time and the settings held.
 
I don't believe you are getting an accurate engine temp. Get an infra red gun to test. Test temp sender as well as the gauge. New doesn't always mean it works.
To constantly run at 145° something can't be right . Unless you are living in 30° weather, it has to be higher.
Fans are intended to be effective at speeds below 40-45 mph. After that, they become a restrction for airflow.
The natural force of the air at speeds above that exceed the fans ability to flow any more air.
So number one is to accurately verify your temps.
Before and after thethermostat. Top and bottom tanks and the core itself.
Pressure test cap. Should be 15-16 lbs. Thermostat 180-195 ° Coolant 50/50% Distilled water to coolant ratio.



Here is a very simplet test to do first. Disconnect power to the fan and run the engine. Now what does the temp gauge say ?
 
MoparLeo said:
I don't believe you are getting an accurate engine temp. Get an infra red gun to test. Test temp sender as well as the gauge. New doesn't always mean it works.
To constantly run at 145° something can't be right . Unless you are living in 30° weather, it has to be higher.
Fans are intended to be effective at speeds below 40-45 mph. After that, they become a restrction for airflow.
The natural force of the air at speeds above that exceed the fans ability to flow any more air.
So number one is to accurately verify your temps.
Before and after thethermostat. Top and bottom tanks and the core itself.
Pressure test cap. Should be 15-16 lbs. Thermostat 180-195 ° Coolant 50/50% Distilled water to coolant ratio.



Here is a very simplet test to do first. Disconnect power to the fan and run the engine. Now what does the temp gauge say ?
Click to expand...

Just FYI, this thread is almost 2 years old . The OP with the temp issue hasn't posted on FABO in almost 2 years either. @mopowers revived it with his new question, but I don't think it's probably worth trying to give advice on the original topic.
 
devilchicken said:
In my case no, all of my settings are saved when the battery is disconnected
Click to expand...

72bluNblu said:
I agree, it holds the settings with the battery disconnected.

I’m sure at some point if it sat long enough they might have to be re-entered, but I know I’ve left my battery switch off for days and even weeks at a time and the settings held.
Click to expand...
Thanks guys. Much appreciated. I'm building my car to be NHRA compliant and since my battery is relocated to the trunk, it requires a cutoff switch that "must stop all electrical functions." I was wondering whether I'd have to reset the controller every time the kill switch was thrown. Not the end of the world, but it's good to know that may not be the case.

Sorry for the thread revival confusion by the way. Sometimes it's easier to just respond to a current thread when researching a topic, than to start a new one.
 
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