scsulliv
Member
I've got a 2020 Ford Expedition MAX Limited, and I use it to tow a 7x14 extra-tall v-nose enclosed trailer from time to time. The trailer is pretty light (around 4000 pounds loaded), but the aerodynamics are absolutely terrible, so any truck that I've pulled it with has really had to work on the highway. I had a 2014 Yukon XL with the 5.3L before my Expedition, and it absolutely struggled to pull this trailer, typically running between 4000 and 5000 RPM on the highway to maintain 65 to 70 MPH. The Expedition does much better, typically running between 2000 and 2600 RPM, with power to spare!
Anyway, I towed the trailer from Chicago to Northern Wisconsin earlier this year, ambient temperature was 75F or so, and I was getting coolant temps up to 235 - 240F on the coolant temp gauge pretty consistently on the highway.
So, I bought the thicker radiator and the higher-powered brushless cooling fans for Expeditions with the HD towing package.
The radiator installation was pretty straightforward (I had to modify the left sealing baffle a bit to make it work, but otherwise it was a drop-in).
However, the brushless fan install is more difficult. First, it uses 3-pin connectors vs. the brushed fan's 2-pin connectors. That's fine, I bought the right connectors.
But - looking at the factory wiring diagrams and comparing the wiring between brushed and brushless fans, things start to get tricky. So I left the 2-speed brushed fan in the truck for now while I try to figure out the wiring and fan cals on the brushless fans. FYI - The thicker radiator helped to improve the cooling performance quite a bit, but I still occasionally get coolant temps up to 235F or so on the gauge with the 2-speed brushed fans, so I'd still like to install the brushless fans if at all possible.
If you look at the wiring diagrams for brushed cooling fans (see the attached files), "LFC" from the PCM controls cooling fan relay 1, so I assume it's a ground signal.
However, for brushless fans, "LFC" from the PCM controls the PWM signal input to the fans. That means that some calibration in some module (probably the PCM) needs to change so that the output from LFC is changed from a ground signal to a PWM signal. As far as I can tell, the brushless fans have controllers built into them, so that all they require is 12V, ground, and a PWM signal in order to work. There are some other minor wiring changes required, too, but those modifications should be pretty straightforward (changes to some relay grounding).
The other part of the equation is that there are likely some fan cal tables that need to be modified to work with the brushless fans, too.
So the question is - does anyone know what calibration needs to change to enable a PWM signal at wire LFC from the PCM? And - is this something that can be modified with a ForScan tool or similar?
Also - is there anyone who has an Expedition with the brushless fans that can share their fan calibration tables? There should be fan cal tables for engine coolant temperature, A/C refrigerant head pressure, and probably transmission and engine oil temperatures as well. Possibly even for things like exhaust temperatures, too.
I'm having a hard time believing that I'm the only one that's tried to do this upgrade on my own. I found this info regarding F150 fan upgrade, but he had the same problem that I do, and no solution is presented: https://www.f150ecoboost.net/threads/2017-f150-fan-swap.83667/
Thanks!
FYI - I upgraded the entire cooling system on my 2014 Yukon XL, too, so this isn't my first rodeo. On that truck I installed the thicker factory radiator with built-in engine oil cooler, ran all of the engine oil cooler lines (with thermostatic controls) to the engine, added the factory auxiliary transmission oil cooler in front of the radiator in addition to the in-tank cooler, installed 900W fans (instead of the stock 700W fans), and had to install a bigger alternator in order to deal with the bigger power draw from the cooling fans. That made a massive difference in transmission temperatures on that truck while towing, and probably helped the coolant and engine oil temperatures out, too.
Anyway, I towed the trailer from Chicago to Northern Wisconsin earlier this year, ambient temperature was 75F or so, and I was getting coolant temps up to 235 - 240F on the coolant temp gauge pretty consistently on the highway.
So, I bought the thicker radiator and the higher-powered brushless cooling fans for Expeditions with the HD towing package.
The radiator installation was pretty straightforward (I had to modify the left sealing baffle a bit to make it work, but otherwise it was a drop-in).
However, the brushless fan install is more difficult. First, it uses 3-pin connectors vs. the brushed fan's 2-pin connectors. That's fine, I bought the right connectors.
But - looking at the factory wiring diagrams and comparing the wiring between brushed and brushless fans, things start to get tricky. So I left the 2-speed brushed fan in the truck for now while I try to figure out the wiring and fan cals on the brushless fans. FYI - The thicker radiator helped to improve the cooling performance quite a bit, but I still occasionally get coolant temps up to 235F or so on the gauge with the 2-speed brushed fans, so I'd still like to install the brushless fans if at all possible.
If you look at the wiring diagrams for brushed cooling fans (see the attached files), "LFC" from the PCM controls cooling fan relay 1, so I assume it's a ground signal.
However, for brushless fans, "LFC" from the PCM controls the PWM signal input to the fans. That means that some calibration in some module (probably the PCM) needs to change so that the output from LFC is changed from a ground signal to a PWM signal. As far as I can tell, the brushless fans have controllers built into them, so that all they require is 12V, ground, and a PWM signal in order to work. There are some other minor wiring changes required, too, but those modifications should be pretty straightforward (changes to some relay grounding).
The other part of the equation is that there are likely some fan cal tables that need to be modified to work with the brushless fans, too.
So the question is - does anyone know what calibration needs to change to enable a PWM signal at wire LFC from the PCM? And - is this something that can be modified with a ForScan tool or similar?
Also - is there anyone who has an Expedition with the brushless fans that can share their fan calibration tables? There should be fan cal tables for engine coolant temperature, A/C refrigerant head pressure, and probably transmission and engine oil temperatures as well. Possibly even for things like exhaust temperatures, too.
I'm having a hard time believing that I'm the only one that's tried to do this upgrade on my own. I found this info regarding F150 fan upgrade, but he had the same problem that I do, and no solution is presented: https://www.f150ecoboost.net/threads/2017-f150-fan-swap.83667/
Thanks!
FYI - I upgraded the entire cooling system on my 2014 Yukon XL, too, so this isn't my first rodeo. On that truck I installed the thicker factory radiator with built-in engine oil cooler, ran all of the engine oil cooler lines (with thermostatic controls) to the engine, added the factory auxiliary transmission oil cooler in front of the radiator in addition to the in-tank cooler, installed 900W fans (instead of the stock 700W fans), and had to install a bigger alternator in order to deal with the bigger power draw from the cooling fans. That made a massive difference in transmission temperatures on that truck while towing, and probably helped the coolant and engine oil temperatures out, too.
