Longgg story short. I dont think I ever had a bad fan. Lots of trial and error. But I've been good for a month. Show 1) there is only one relay on ny 2013. Its labeled low speed. So all else aside, that is a cheap easy way to atleast eliminate one potential problem. Hope this helps somebody! @agent86 ,Bob, the electric cooling fan HI and LOW relays are located in the power distribution center (PDC) under the hood/engine compartment. Fuse and relay layout label affixed to the inside surface of the PDC cover for cooling fan relay identification and location. Also check out the attached link, diagnosing cooling fan problems, good article fuses,relays, fan motor,etc. Good luck. I hope this helped you out, if so let me know by pressing the helpful button. http://www.jk-forum.com/how-tos/a/jeep-w... Recently, I was driving my 2015 Jeep Wrangler JK Unlimited through a parking lot on a 95 degree day, and after leaving a stop sign, a check engine light flashed on (later I would learn it was a P0480 Cooling Fan Relay 1 Control Circuit), and shortly thereafter my Jeep overheated. What followed was a multi-day Google searching and diagnostic session, which made me realize there is a lack of
information as well as a lot of mis-information about the 3.6L “Pentastar” Jeep Wrangler model years, and how the radiator fan works. This is my summary of what I learned about the cooling fans on these Jeeps, so hopefully more people can diagnose issues themselves. Once the code triggered on my Jeep, I immediately pulled over and parked, but I left the engine running. Thankfully, my stereo has
an OBDII diagnostic link, so I was able to immediately get the code, which as mentioned above was a Unfortunately, I quickly hit a dead-end. The internet knowledge of the 3.6L pentastar fan setup is woefully inadequate. I suspect there are a few reasons for this:
Here are some of the articles I hit (a sampling):
I found a lot more than this as well - the forums are full of P0480 knowledge, but very little of it touches this model. To recap, the 2011 and earlier Jeep JKs (with the 3.8L engine) have a fan setup with these characteristics:
As you can probably tell, I have collected a good bit of knowledge about the earlier Jeep JK fans. My hope was there would be a lot of parallels between the two powertrains; after all there are already relays and fuses and other equipment already in the Jeep for this; surely for cost savings they would reuse most of that with the newer engine. Unfortunately I have since learned that nearly all of this is incorrect for my Jeep. The 2012 and up Jeep JK wrangler fan on the 3.6L Pentastar has a few key characteristics:
Now, typically, a system like the old JK setup will have relays to do “high amperage” power switching. For example, if a fan needs 60 amps to run on high speed, the high speed relay acts as a large switch which, when enabled, sends the high amperage power to the fan to run. As soon as the power reaches the fan, it kicks on. However, given the description above you’ll notice the only voltage going to the fan (other than the piddly PWM wire) is coming directly from the battery; no relays, and therefore no external control. What that means is all of the circuitry for enabling the fan and controlling the fan speed is contained inside the fan assembly itself. The fan expects to get power from the battery at all times (so it can run even when the car is off), and translates the PWM duty cycle signal from the computer in the TIPM into a variable speed for the fan itself. Consequently, the fan for a 2011 and prior JK Jeep is around $65 to $200 dollars, and there is a ton of aftermarket competition. However, the “fan assembly” for the Pentastar is pretty much only made by Mopar (Part 68143894AB), and it costs $400 on a good day. Part of the reason for a lack of an aftermarket is the complexity of having to reproduce a competitively priced setup that can do the same thing while keeping the factory computer from throwing codes. To work with the factory setup, any fan assembly has to:
Aside from this complexity, another major reason there isn’t much aftermarket is that the 3.6L fan itself is actually pretty good. The outrunner design makes it efficient and reliable, and based on others’ testing, even in heavy off-roading setups the 3.6L fan is able to keep up just fine. So, I knew that the fan wiring seemed deceptively simple. But what I also knew was that there are tons of parts under the hood that are labeled as belonging to the fan. Notably:
I checked and re-checked all of this in hopes of a cheap and easy fix. You can see some of my research notes here: P0480 - How to Diagnose 3.6 PWM Fan Issues However, as it turns out, none of this is used for the radiator fan. As best as I can tell, some of this is leftovers from the old design, and some of this is likely used for other things (I suspect the fan relays are actually for the blower motor and AC system, though I don’t know for certain). I stared at this wiring diagram (found here thanks to BBB Industries), trying to figure out why the above components weren’t on it. The Sparse Wiring Schematic for 2013+ Jeep Cooling Fans Why aren’t the components on it? Simple: they aren’t used! Also, as far as I could tell, the only code the fan will ever throw on these newer jeeps is P0480, which is all encompassing to mean the TIPM asked the fan to turn on, and couldn’t detect that it did, or the engine overheated under a certain MPH and the computer doesn’t know why. Assuming you are getting valid temperature readings from the engine temp sensors, the only components you have to worry about when diagnosing the 2012+ Pentastar 3.6L JK radiator fan not running are:
Here are some pictures for orientation after I dismantled my engine compartment to trace everything as a last ditch effort before taking it to the dealership. The Fan Harness with Three Wires The Ground Location The Fusible Link Connecting to the Battery Unfortunately, testing the TIPM output requires a TIPM diagnostic tool (dealer equipment) or at least an oscilloscope so you can visualize the duty cycle square-wave coming from the PWM signal (even if you don’t know it’s right, seeing it would add confidence). It’s not something I was able to ever actually capture using my multimeter. Also unfortunately, you cannot simply bench-test the fan. Believe me, I tried. If you jump the fan to power and ground and try to provide a direct 12V signal to the PWM lead, nothing will happen and you will think your fan is broken, when in actuality it may just be ignoring the signal because it is not a valid duty cycle. So, inevitably you may have to go to the dealership for a diagnosis (or you may just blindly replace the fan and the TIPM for a cool $1000 in parts and a bunch of time in your own garage), however, before you do that, it’s worth checking everything else. So, what was it in my case? Shockingly simple: The 10mm nut holding the fusible link to the battery had worked itself loose. It was still touching, but it was not a tight fitting. As a result, I was testing the power to the fan with a multimeter and getting a solid 12-14 volts, but the connection was not reliable enough to provide the high amperage demands of the fan, so the fan was not running, and the code was being thrown. If I had to play nostradamus, I’d guess that months ago when I installed my stereo I managed to back this nut off some (likely on accident) and didn’t notice. It just finally worked itself loose with enough bumps and jerks to make the fan unhappy. If that isn’t your case, the other two likely causes:
Thankfully, both the TIPM and fan assembly are relatively easy to remove and replace based on my research. I nearly had the fan out of my Jeep in 15 minutes after removing the air box and some of the surrounding parts to verify the wiring (however, it turns out I didn’t need to). This article describes the TIPM replacement process – while I didn’t have mine completely out, I did have it unbolted from the Jeep and was able to see under the unit. It’s expensive, but not hard to swap out. Good Luck Jeep owners! Where is the cooling fan relay at?The fan relay is usually located near the bottom of the engine compartment on a metal frame member. The metal acts as a heat sink to keep the fan relay cool. So, unplug the connector at the relay and repeat the check for power.
Is there a relay for the radiator fan?The cooling fan relay is an electromagnetic switch that controls the power supply to the engine's cooling fans. It ensures that the energy-intensive devices only run when needed, usually when the vehicle is immobile.
What happens when a fan relay fails?If the relay fails, it will be unable to supply power to the fans, and as a result they will not operate. This can lead to overheating, especially when the vehicle is at a stop, where there is no forward motion by the vehicle to pass air over the radiator.
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