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The Bacon Hauler (‘12 Cop Charger)
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Discussion Starter · #1 ·
The cooling fans that bolt to the back of the radiator and pull air through it are NOT variable speed. They are either on and turning full speed or off and not turning at all (under their own power.

Can anyone confirm my assertion there?

That is what I believe to be the case, but recent observations would seem to invalidate it, so trying to clear things up.
 

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yes - single speed fans.

I don't know if the ones that have dual fans (does Pursuit Package have dual fans? @Nuke)

On my last GM vehicle - it had dual fans.

The primary one ran with A/C and 'regular' cooling needs. If the coolant temp got higher yet, it would kick on the 2nd fan as well for additional cooling.

the Challengers with 6.1 / 6.2 SC / 392/6.4 engines have dual cooling fans - part of the Severe Duty II cooling system these are equipped with
 

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The Bacon Hauler (‘12 Cop Charger)
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Discussion Starter · #3 ·
Yep, dual fans in the shroud that bolts to the radiator.

At the moment the coolant temp won’t get over 192F, and when I directly observe the fans, they are both spinning, albeit at a very slow speed. I cannot hear them spinning anyway, which is the opposite of what I am used to.

Normally when they kick on, there is no doubt they are energized and spinning, as the noise is unmistakable.

Starting to wonder if removing and reinstalling that unit 8 times was one time too many, and now it needs to be replaced...

Oh well, if it does, I bet I can do the job in no time flat, as I am well versed in extracting that puppy with everything still in place on the engine!
 

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Yep, dual fans in the shroud that bolts to the radiator.

At the moment the coolant temp won’t get over 192F, and when I directly observe the fans, they are both spinning, albeit at a very slow speed. I cannot hear them spinning anyway, which is the opposite of what I am used to.

Normally when they kick on, there is no doubt they are energized and spinning, as the noise is unmistakable.

Starting to wonder if removing and reinstalling that unit 8 times was one time too many, and now it needs to be replaced...

Oh well, if it does, I bet I can do the job in no time flat, as I am well versed in extracting that puppy with everything still in place on the engine!
you could block the front of the radiator with cardboard (vehicle stationary) to reduce airflow to get temperature up higher to see what happens
 

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The Bacon Hauler (‘12 Cop Charger)
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Discussion Starter · #5 ·
I’m thinking I will use my tuner to lower the temp at which the fans should engage to see if any change. If not, I can unplug the assembly and test the wiring harness plug voltages just to be sure.

The ambient temps here are currently hovering around 32F thankfully, so the fans aren’t really needed to keep it cool. But this weekend will bring 70F, so I gotta get this figured before then.
 

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2014 Shaker Boosted 392 Stroker M6
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The cooling fans that bolt to the back of the radiator and pull air through it are NOT variable speed. They are either on and turning full speed or off and not turning at all (under their own power.

Can anyone confirm my assertion there?

That is what I believe to be the case, but recent observations would seem to invalidate it, so trying to clear things up.
What exactly is the problem you're having anyhow? With the pursuit package your Charger should have much more cooling capability than stock as far as I know.
 

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The Bacon Hauler (‘12 Cop Charger)
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Discussion Starter · #7 ·
The cooling fans that bolt to the back of the radiator and pull air through it are NOT variable speed. They are either on and turning full speed or off and not turning at all (under their own power.

Can anyone confirm my assertion there?

That is what I believe to be the case, but recent observations would seem to invalidate it, so trying to clear things up.
What exactly is the problem you're having anyhow? With the pursuit package your Charger should have much more cooling capability than stock as far as I know.
I have not heard the fans kick on since I reinstalled the fans last night, despite reaching normal operating temp several different times since. I can see them moving, but not so fast as to make a loud whirring noise like I am used to.

No overheating, temps are fine, but I am concerned the assembly is not working as it’s supposed to now, for whatever reason.
 

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2014 Shaker Boosted 392 Stroker M6
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I have not heard the fans kick on since I reinstalled the fans last night, despite reaching normal operating temp several different times since. I can see them moving, but not so fast as to make a loud whirring noise like I am used to.

No overheating, temps are fine, but I am concerned the assembly is not working as it’s supposed to now, for whatever reason.
I do not know if our fans have an external controller like after-market e-fans do, but I doubt it. It sounds to me like the problem is in the PCM, but I don't have any wiring diagrams to really make an educated stab at a solution. I have an after-market fan on my Ram that only runs at one speed, and the controller for it has a dial to adjust the temperature to activate the fan. I have the controller mounted on the frame above the radiator, and switched power going to the fan that is cut off with the ignition switch to keep the fan from draining my battery with the engine off. It gets hot enough here for the fan to come on by itself when my Moose is parked. :surprise:
 

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The Bacon Hauler (‘12 Cop Charger)
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Discussion Starter · #9 ·
I’m leaning toward the fans’ controller in the assembly being hosed. When draining the previous radiator yesterday, the drain valve got stuck in such a position so as to cause the coolant to spray out several inches, and as I turned the valve with my screw driver, it was hiding down everything within 8 inches in the engine bay like some kind of hot coolant sprinkler.

I am wondering if that caused a problem in the controller when it next energized.

Ugh, I feel like I could get this figured out in 30 minutes if I could just go home and get started. But instead of doing something useful like that, I am stuck on a conference call that is headed into it’s 3rd hour now with no signs of ending before 4pm.

I HATE CONFERENCE CALLS!!

They are evil, boring, and the unholy spawn of the Devil and something else that is bad...

Calgon, take me away!!
 

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The controller should be a completely sealed unit, but if there are exposed wires anywhere in the system, a short would fry it for sure.
 

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The Bacon Hauler (‘12 Cop Charger)
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Discussion Starter · #11 ·
The controller should be a completely sealed unit, but if there are exposed wires anywhere in the system, a short would fry it for sure.
Sealed is just another word for secrets, and if there is something I will NOT abide, it is the keeping of secrets in my car.

I ain’t Heidi Klum, and I don’t sing R&B, so when I run across something that’s sealed, it gets decidedly UNsealed around here!
 

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A fixed speed motor running at a lower than normal speed means not as much of those electron thingies getting to the motor as normal.....that is....something is syphoning your power electrons away from their intention-ed destination. Either a partial short/ground somewhere in the power curcuit, or a somebody's been blowing in the radiator too much.
 

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Hi Nuke

The cooling fans that bolt to the back of the radiator and pull air through it are NOT variable speed. They are either on and turning full speed or off and not turning at all (under their own power.

Can anyone confirm my assertion there?

That is what I believe to be the case, but recent observations would seem to invalidate it, so trying to clear things up.

Not quite correct, you do not say what year your car is but this is from the 2012 Shop Manual for an SRT




Cooling Fan Modes of Operation

The two speed cooling fan system uses three relays to control the cooling fan operation. These are the Series-Parallel Fan Relay, Lo-Hi Fan Relay and Hi-Med. Fan Relay. During low speed mode, the cooling fan and cooling fan resistor operate in series, splitting the 12 Volt source between the the resistor and the cooling fan motor. During high speed mode, the cooling fan motor and resistor operate in parallel to one another, with each receiving a separate 12 Volt source.

During low speed mode: The PCM grounds the (N201) Fan Relay Control circuit, closing the relay to connect the (A16) Cooling Fan 12 Volt Supply circuit to the (N23) Cooling Fan Motor 1 Output circuit. The (N23) Cooling Fan Motor 1 Output circuit supplies 12 Volts DC to cooling fan resistor. Current flows through the resistor to the (N210) Cooling Fan Lo-Hi Control circuit. The current passes through the Lo-Hi Fan Relay to the (N24) Cooling Fan Motor 2 Output circuit and on to Cooling Fan Motor. The (Z903) Ground circuit provides the ground path for the Cooling Fan series circuit.

During High speed mode: The PCM grounds the (N201) Fan Relay Control circuit and the (N112) Fan Relay Control circuit, closing all three Cooling Fan Relays. The (A16) Cooling Fan 12 Volt Supply circuit connects to the (N24) Cooling Fan Motor 2 Output circuit through the Series-Parallel Fan Relay and provides 12 Volts to Cooling Fan Motor 2. The (Z903) Ground circuit provides the ground for Cooling Fan Motor 2. The (A16) Cooling Fan 12 Volt Supply circuit connects to the (N23) Cooling Fan Motor 1 Output circuit through the Hi-Med. Fan Relay and provides 12 Volts through the cooling fan resistor. The (N210) Cooling Fan Lo-Hi Control circuit connects to the (Z903) Ground circuit through the Lo-Hi Fan Relay to provide the ground path for the cooling fan resistor.




Regards

Dereck
 

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The Bacon Hauler (‘12 Cop Charger)
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Discussion Starter · #14 ·
It’s a 2012.

After reading that and viewing the spec image, I’m now thinking it’s possible I am observing the expected behavior of the fans when the ambient temps are as low as they are now, which is good. I will try to confirm that hyposthesis when I get home.

However, in trying to take all that information in and make sense of it, something caused my brain to partially explode.

I was able to shove most of the prolapsed grey matter back in through my ear hole, so I think I’m good, but now I need to find a new pen...and I have a terrific headache...and I can taste music all of a sudden.

Speaking of, when did Metallica’s And Justice for All.. album start tasting like venison sausage? I never noticed that before, but it’s sure prevalent now...

So hungry...

Thanks for the info @Dereck!!

Hi Nuke

The cooling fans that bolt to the back of the radiator and pull air through it are NOT variable speed. They are either on and turning full speed or off and not turning at all (under their own power.

Can anyone confirm my assertion there?

That is what I believe to be the case, but recent observations would seem to invalidate it, so trying to clear things up.

Not quite correct, you do not say what year your car is but this is from the 2012 Shop Manual for an SRT




Cooling Fan Modes of Operation

The two speed cooling fan system uses three relays to control the cooling fan operation. These are the Series-Parallel Fan Relay, Lo-Hi Fan Relay and Hi-Med. Fan Relay. During low speed mode, the cooling fan and cooling fan resistor operate in series, splitting the 12 Volt source between the the resistor and the cooling fan motor. During high speed mode, the cooling fan motor and resistor operate in parallel to one another, with each receiving a separate 12 Volt source.

During low speed mode: The PCM grounds the (N201) Fan Relay Control circuit, closing the relay to connect the (A16) Cooling Fan 12 Volt Supply circuit to the (N23) Cooling Fan Motor 1 Output circuit. The (N23) Cooling Fan Motor 1 Output circuit supplies 12 Volts DC to cooling fan resistor. Current flows through the resistor to the (N210) Cooling Fan Lo-Hi Control circuit. The current passes through the Lo-Hi Fan Relay to the (N24) Cooling Fan Motor 2 Output circuit and on to Cooling Fan Motor. The (Z903) Ground circuit provides the ground path for the Cooling Fan series circuit.

During High speed mode: The PCM grounds the (N201) Fan Relay Control circuit and the (N112) Fan Relay Control circuit, closing all three Cooling Fan Relays. The (A16) Cooling Fan 12 Volt Supply circuit connects to the (N24) Cooling Fan Motor 2 Output circuit through the Series-Parallel Fan Relay and provides 12 Volts to Cooling Fan Motor 2. The (Z903) Ground circuit provides the ground for Cooling Fan Motor 2. The (A16) Cooling Fan 12 Volt Supply circuit connects to the (N23) Cooling Fan Motor 1 Output circuit through the Hi-Med. Fan Relay and provides 12 Volts through the cooling fan resistor. The (N210) Cooling Fan Lo-Hi Control circuit connects to the (Z903) Ground circuit through the Lo-Hi Fan Relay to provide the ground path for the cooling fan resistor.




Regards

Dereck
 

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Hi Nuke




Not quite correct, you do not say what year your car is but this is from the 2012 Shop Manual for an SRT




Cooling Fan Modes of Operation

The two speed cooling fan system uses three relays to control the cooling fan operation. These are the Series-Parallel Fan Relay, Lo-Hi Fan Relay and Hi-Med. Fan Relay. During low speed mode, the cooling fan and cooling fan resistor operate in series, splitting the 12 Volt source between the the resistor and the cooling fan motor. During high speed mode, the cooling fan motor and resistor operate in parallel to one another, with each receiving a separate 12 Volt source.

During low speed mode: The PCM grounds the (N201) Fan Relay Control circuit, closing the relay to connect the (A16) Cooling Fan 12 Volt Supply circuit to the (N23) Cooling Fan Motor 1 Output circuit. The (N23) Cooling Fan Motor 1 Output circuit supplies 12 Volts DC to cooling fan resistor. Current flows through the resistor to the (N210) Cooling Fan Lo-Hi Control circuit. The current passes through the Lo-Hi Fan Relay to the (N24) Cooling Fan Motor 2 Output circuit and on to Cooling Fan Motor. The (Z903) Ground circuit provides the ground path for the Cooling Fan series circuit.

During High speed mode: The PCM grounds the (N201) Fan Relay Control circuit and the (N112) Fan Relay Control circuit, closing all three Cooling Fan Relays. The (A16) Cooling Fan 12 Volt Supply circuit connects to the (N24) Cooling Fan Motor 2 Output circuit through the Series-Parallel Fan Relay and provides 12 Volts to Cooling Fan Motor 2. The (Z903) Ground circuit provides the ground for Cooling Fan Motor 2. The (A16) Cooling Fan 12 Volt Supply circuit connects to the (N23) Cooling Fan Motor 1 Output circuit through the Hi-Med. Fan Relay and provides 12 Volts through the cooling fan resistor. The (N210) Cooling Fan Lo-Hi Control circuit connects to the (Z903) Ground circuit through the Lo-Hi Fan Relay to provide the ground path for the cooling fan resistor.




Regards

Dereck
By any chance, do you know the part numbers for those 3 relays? I would like to get new ones for my 2012 Challenger RT.

Keith
 

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2014 Shaker Boosted 392 Stroker M6
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By any chance, do you know the part numbers for those 3 relays? I would like to get new ones for my 2012 Challenger RT.

Keith
Weird! Everyone here knows what Nuke drives, or rather repairs every chance he gets...
 

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Basically, the dual fans operate on low speed sourced by one of the relays, or say both are using the same 12v feed.
When high speed is called for, each fan uses its own relay 12v feed.

If you are testing fans for temp settings in the tune shut off the HVAC because they can be triggered by the system pressure and such.
 

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My 2012 SRT392 is having two fans. But I see only one fan spinning. When does the second fan kicks in? Switching on airco or off does not affect the second fan. It simply does not run.


Anybody?
 

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Check Fuse #2 (Fan1) and Fuse #18 (Fan2) They are both supposed to run together in any mode, they never run singularly.
You may have a bad motor if its not wiring?
When the motors go bad either the brushes wear down or a bearing drags. You can test fire the fans with AlfaOBD. If bad you can hear a faint whine noise.
The right and left fan motors have different part numbers. Got mine on rock auto.

You can drop the fans out the bottom if on 9-inch ramps or higher.
Automotive tire Wood Automotive design Motor vehicle Engineering


The fans bolt onto the motors with a left hand nut.
Automotive tire Automotive lighting Wheel Motor vehicle Alloy wheel


Wheel Automotive tire White Light Product


Good luck
 
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