Engine cooling fan not working.

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#1
Hey guys I havent posted in a while due to my frustration with my FIST, at 52,000 miles motor went south but good thing for warranty, coolint in number 3 cyl before the motor was done. Probably heat related as my car drove hot and was overheating last summer. 10,000 miles into my new motor and warm temps mean overheating is back but this time the engine cooling fans not working. Looked at it last night and the wire plug going to the fan from the module is burnt up. WTF??? Anybody have any advise? New fan and module? Thanks COOP
 


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Rocketst

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It was repaired under warranty right? Is it possible to take it back to Ford and get them to repair this as well? They should have touched almost everything in the engine bay if they took the motor out. Even if it was just the head gasket that needed to be replaced they have to remove a good portion of the main wiring harness to get the head out.

Edit:remove meaning just unplugging things and moving it off to the side. It could be their fault it's damaged.
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Rocketst

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#3
Also, that looks like the current grounded to the harness itself. So you have an electrical issue somewhere. They aren't easy to find most of the time.

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Thread Starter #4
I wish I could prove it was their fault but I cant be without the car right now and I'd rather fix it myself as the dealership had it for 3 1/2 weeks to replace the engine. I probably need a fan assy and the module? IDK
 


Rocketst

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#5
Search for harnesses at fordparts.com you can order just the harness from them and wire it in yourself. You need to find that ground though otherwise it's going to happen again.

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HardBoiledEgg

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STOP BLAMING DEALERS

NO WAY A ENGINE JOB CAN CAUSE THE FANS TO BURN OUT. PARTS GO BAD GUYS. CRAZY THOUGHT I KNOW
 


Rocketst

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Lol not when a part grounds like his did.

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#10
Are you also experiencing a dead battery if the car sits unused for three or more days?
 


HardBoiledEgg

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#11
WE REPLACE PARTS ALL THE TIME THAT ARE BURNT LIKE THAT. ID BE SELLING YOU THE CONNECTOR TOO
 


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Thread Starter #12
I bought a new fan assembly with the module and hoping to replace it tonight. Any videos on how to just replace the fan assembly? Cant find anything on youtube for a ST fan replacement? COOP
 


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#13
STOP BLAMING DEALERS

NO WAY A ENGINE JOB CAN CAUSE THE FANS TO BURN OUT. PARTS GO BAD GUYS. CRAZY THOUGHT I KNOW
Thank you lol. There are bad dealers and techs, but just because someone did something doesn't mean it's their fault entirely (cue meme: got my oil changed, now my daughter is pregnant). We see this so often (mainly older cars though), most likely the fan motor has a high resistance and causing an excessive current draw. That high draw then causes more heat leading to a melted plug. Either that or poor pin fitment in the connector, also causing excessive heat due to poor contact. Heck, be glad you don't have a '15/'16 F-150! Seen a few requiring a new BJB, harness, and fans due to melted high-speed fan relay connectors.

OP: Replace the fan assembly (new OEM includes resistor and harness from resistor to fan). If the burnt connector is at the resistor/speed controller though, you're SOL and have to buy a new harness or get the connector from a junkyard car. Harness number is 14K012. Also, use heat shrink when crimping. Don't know if you already replaced the fan, but I find it easier to remove the sound synthesizer and post-intercooler charge pipe all the way up to the intake. Remove the airbox too. The fan clips to the top with pop tabs, rotate CCW, and remove from the bottom.
 


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It took a lot of amperage to do that. It means the wire was directly grounded or a failure within the motor caused a short circuit. What ever the cause you will find it by looking for scorch marks somewhere along that electrical path. Do you best to find that because until you do you'll be shorting that connector every time you put power to it. Because there was enough current there to weld that short circuit solid.

I'll also suggest that you stop trying to make your undersized radiator work. The stock radiator on these cars is usable in in a northern state as long as the temps are below 85 but even then you'll notice the fuel economy gets worse due to the engine pulling timing. I expect there also a corresponding loss in power. Put in a Mountune radiator and you'll not only gain about 3 to 4 mpg when it's hot but you'll also find that 2nd gear will roast your tires if you don't keep the traction control engaged.
 


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Intuit

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The fact that it has only two pins means it's not a PWM fan.
* The circuit is not capable of drawing more than the amount on the fuse.
* The wiring and connectors will be rated to handle ≥ what the fuse is.
* Assuming the fuse didn't blow, your fault lies merely with the connector.

Simply replace the wire harness connectors and you'll be good. You can solder in your own wire harness so long as they're rated to handle at minimum, what's on the circuit fuse.

Sometimes people use Add-A-Circuit type products in vehicles and they unfortunately have a sdubidly flawed design that can result with overheated wire, breaching its own insulation, melting through another, and joining unrelated circuits, DEEP within some wire harness buried DEEP inside a vehicle where you'll "never" find it.

1624767411167.png
1624769852133.png
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It is assumed that the fuses power the relays.

Baring the possibility of aforementioned owner modifications, the connector was either manufactured incorrectly (alloy composition), or was allowed to begin corroding. If the seal was bad and water was allowed in, that would do it. When the connector corrodes, it's alloy composition changes in a way that causes it to convert more of the passing energy into heat; like a resistor. The additional heat in-turn accelerates corrosion and we wind up with a runaway condition. A bad connection, due to partial contact for example, can result with the same problem. Once that metal is allowed to overheat even once, its composition can change and may no longer be up to spec.
 


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#17
Going to bump this thread instead of making a new one about the same topic.

Does anyone know where I can get a new connector from the fan to the control module? Exact one shown in the OP's pic. Either new or a compatible model that I can pull from salvage would work, but preferably something I can get tomorrow.

Thanks!
 


TyphoonFiST

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#18
Going to bump this thread instead of making a new one about the same topic.

Does anyone know where I can get a new connector from the fan to the control module? Exact one shown in the OP's pic. Either new or a compatible model that I can pull from salvage would work, but preferably something I can get tomorrow.



Thanks!
Here is a PDF ..I've used it many times and found my connector @ Amazon....Rockauto and Stealership.

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.motorcraft.com/content/.../wire_sets_wiring/18376-Pigtail-Book-2016.pdf
 


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#19
I had/have this same problem. My original fan stopped working a couple weeks ago out of the random. Noticed fan plug was burned like above. Also the inside of the control module, the corresponding pin was melted somewhat and corroded. Purchase new OEM fan and installed it. New module, new connector and all is well. Today, which is just two weeks later, the fan stops working again. Same issue, but this time the opposite electrode is showing signs of heat damage. Sent 12v to the fan directly to make sure it's not fried and it works fine. I filed off the corrosion and applied some dielectric grease inside the fan connections side of the module. I also slightly twisted the pins to make a better connection. Fan started working again.

When originally replacing the fan, I removed the battery and tray and cleaned off all the harness to body grounds which did have some minor corrosion. I'm wondering if this has anything to do with my Battery getting weak. I've been putting off changing it, but it's def on its last leg. Maybe it's causing some voltage drop and stressing the electrical system? The fan runs on high speed almost all the time since it's been 98dg plus here lately. My coolant temps never go above 194 when cruising and usually only go above 200 during a pull. I am on the factory radiator. I plan on replace the battery ASAP. The negative terminal side is corroding and that has ever happened before the battery started showing signs of failure.
 


XR650R

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#20
I had/have this same problem. My original fan stopped working a couple weeks ago out of the random. Noticed fan plug was burned like above. Also the inside of the control module, the corresponding pin was melted somewhat and corroded. Purchase new OEM fan and installed it. New module, new connector and all is well. Today, which is just two weeks later, the fan stops working again. Same issue, but this time the opposite electrode is showing signs of heat damage. Sent 12v to the fan directly to make sure it's not fried and it works fine. I filed off the corrosion and applied some dielectric grease inside the fan connections side of the module. I also slightly twisted the pins to make a better connection. Fan started working again.

When originally replacing the fan, I removed the battery and tray and cleaned off all the harness to body grounds which did have some minor corrosion. I'm wondering if this has anything to do with my Battery getting weak. I've been putting off changing it, but it's def on its last leg. Maybe it's causing some voltage drop and stressing the electrical system? The fan runs on high speed almost all the time since it's been 98dg plus here lately. My coolant temps never go above 194 when cruising and usually only go above 200 during a pull. I am on the factory radiator. I plan on replace the battery ASAP. The negative terminal side is corroding and that has ever happened before the battery started showing signs of failure.
Weak batteries are the #1 gremlin we see here.
Spend the money. Get a new one.
95% likely to fix it.
 


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