Electric Fan Control using the LX fans

[dartslantsix]

I’m starting to dig into which swap harness I’m going to purchase. That has taken me down the rabbit hole of electric fan control. I’ve got a 2010 5.7L from a Police Charger and I’m planning to use the radiator and dual fans from the Charger.

It appears that 2014+ PCMs can control the fans and the swap harness is set up to do this. Can I update my engine to use the newer PCM? I’ve heard there was a reluctor ring change in 2014 that may prevent me from updating to the newer PCM. Can anyone confirm?

If I can’t go that route, there are a number of electric fan controllers and/or relay systems to run the fans. Are there any recommendations? I’d love to go pulse width modulation (PWM) if there is an affordable controller that is reliable. I’m seeing mixed reviews about some brands that die randomly.

Lastly, is there a way to figure out how many amps these fans pull?

Thanks.

 

[goldduster318]

Don't know too much about the PCMs, but for fans. The Dakota Digital fan controller has a lot of features. I wouldn't worry that much about having PWM honestly. It's reliable because it just opens and closes a relay or two depending on if you have dual speed. Honestly I think you could use the resistor/diode block from a Ford Contour Fan on virtually any fan to make it dual speed if you wanted.

As far as testing, you just need a multimeter with the amp clamp like this and put it around the power or ground during testing. This is with peak hold for a contour fan -> so the inrush was 65.2 A.

https://www.amazon.com/KAIWEETS-Mul...ture-Capacitance/dp/B07Z398YWF/?tag=fabo03-20

Generally it seems like a good general use multimeter.

 

[DionR]

I'm not absolutely certain, but pretty sure the earlier VVT motors will run on the 2015+ PCM's as long as the crank (and cam) sensor that matches the PCM used. I know the number of teeth didn't change, only the width of the space or the ring (can't remember which).

I will see if I can find info to back that up.

At one point I started to lean towards using a GPEC2 controller just because the PCM has control of the fans. But in the end I decided to stick with the NGC controller so I didn't have to get a Crate Motor tune or deal with the SSR stuff. Which is kind of funny now that I think about it, because now that I am going down the path of running a TIPM to simplify my wiring and control my fans, I have to have a SSR module of some type or run the factory WIN module. And that rabbit hole lead me down another whole path of "what-ifs" that has my head spinning right now.

 

[dartslantsix]

I'm not absolutely certain, but pretty sure the earlier VVT motors will run on the 2015+ PCM's as long as the crank (and cam) sensor that matches the PCM is used. I know the number of teeth didn't change, only the width of the space or the ring (can't remember which).

I will see if I can find info to back that up.

At one point I started to lean towards using a GPEC2 controller just because the PCM has control of the fans. But in the end I decided to stick with the NGC controller so I didn't have to get a Crate Motor tune or deal with the SSR stuff. Which is kind of funny now that I think about it, because now that I am going down the path of running a TIPM to simplify my wiring and control my fans, I have to have a SSR module of some type or run the factory WIN module. And that rabbit hole lead me down another whole path of "what-ifs" that has my head spinning right now.

I asked Sublime about using the newer PCM with the 2010 tone ring and this is what I got:

2015+ is able to be unlocked and control fans but results vary on using them with an older reluctor wheel. Some say that you can run the 2015+ crank position sensor and be fine but we have no personal experience with this.

So, unless I see something definitive, I should probably stick with my 2010 PCM and use the Dakota Digital fan controller.

Side note, when I was researching this I saw @DionR posting about it on the Challenger talk forum. He's been a lot of help, even back when my car was Magnum swapped. Thanks, man.

 

[DionR]

I asked Sublime about using the newer PCM with the 2010 tone ring and this is what I got:

So, unless I see something definitive, I should probably stick with my 2010 PCM and use the Dakota Digital fan controller.

I can't find anything definitive. I think I was reversing things in my mind and thinking about a later motor with an NGC rather than an earlier motor with a GPEC2. I did ask Chris at Hotwire Auto about the later motor and NGC setup (my motor is a 2017, PCM is a 2010 Ram) and he said as long as the crank sensor matches the PCM it will work. But that's not an earlier motor with a GPEC2 like you are looking at.

My brother bought a harness and PCM from Hotwire and it was a GPEC2, so I know they are using those PCM's now. Maybe reach out to them? They might have some insight and personal experience.

BTW, I think the cam sensor has nothing to do with it. I mentioned it above, but I think I am wrong.

Side note, when I was researching this I saw @DionR posting about it on the Challenger talk forum. He's been a lot of help, even back when my car was Magnum swapped. Thanks, man.

Thanks for that. Glad to be helpful.

For what it's worth, I've been reading your blog since I found it when you were doing your IRS project on your Dart. Always enjoyed your projects.

 

[dartslantsix]

For what it's worth, I've been reading your blog since I found it when you were doing your IRS project on your Dart. Always enjoyed your projects.

Was that during the Cardomain/Autoholics era? I really miss the Autoholics site. A company bought them out and completely destroyed it.

 

[DionR]

Was that during the Cardomain/Autoholics era? I really miss the Autoholics site. A company bought them out and completely destroyed it.

It might have been! Can’t say for sure now, I’ve slept since then, but Cardomain does seem familiar.

 

[dartslantsix]

Just got a response from Hotwire:

Yes, you can go to the 2015+ ecu. (depending on which transmission you are using) You just have to swap to the 2015 crank sensor.

After we flash the 2015+ ecu to a "hotrod" calibration, it has a single relay control output. You can set up the fan relay(s) but it will not be 2 speed. If you want to maintain high/low control then you might still want to go with an aftermarket fan controller.

So it can be done! Unfortunately, the fans will be full throttle when triggered.
At this point, I think it makes more sense to use my NGC pcm and use a separate fan control. That way I can make use of the dual speeds.

Further learning on the dual fan LX kit:
The factory used 3 relays. On low speed the fans are run in series, effectively running them at 6 volts. On high speed, the fans are run in parallel, giving them full 12 volts. One of the fans spins at a higher RPM than the other.

Still need to test the amperage of the fans.

Regarding controllers:
I'd love to try a PWM controller, but everything I'm finding is expensive and the reviews say they're unreliable.

The Dakota Digital controller ($185, seems reliable) can run 2 fans, but it would turn on one fan for "low" and then both for "high". Not the same as the factory logic, but probably fine. Maybe a bit louder?

I found this controller: HPC ($179.99) that can run the fans like the factory did. Not much reliability info online, although their Ebay reviews are all good.

 

[DionR]

Just got a response from Hotwire:

So it can be done! Unfortunately, the fans will be full throttle when triggered.
At this point, I think it makes more sense to use my NGC pcm and use a separate fan control. That way I can make use of the dual speeds.

Further learning on the dual fan LX kit:
The factory used 3 relays. On low speed the fans are run in series, effectively running them at 6 volts. On high speed, the fans are run in parallel, giving them full 12 volts. One of the fans spins at a higher RPM than the other.

Still need to test the amperage of the fans.

Regarding controllers:
I'd love to try a PWM controller, but everything I'm finding is expensive and the reviews say they're unreliable.

The Dakota Digital controller ($185, seems reliable) can run 2 fans, but it would turn on one fan for "low" and then both for "high". Not the same as the factory logic, but probably fine. Maybe a bit louder?

I found this controller: HPC ($179.99) that can run the fans like the factory did. Not much reliability info online, although their Ebay reviews are all good.

Interesting, I wondered how the relays worked. Where did you come up with that info?

Makes me glad to be working towards the using the TIPM.

 

[dartslantsix]

Interesting, I wondered how the relays worked. Where did you come up with that info?

Makes me glad to be working towards the using the TIPM.

I dug it up from on of the LX forums or maybe Challengertalk. Found it in a couple places. My donor fuse block has three relays and after finding that info, it makes sense.