It has happened to me! (Dreaded Fan Sensor - Crumbling Hose!)

[TJC]

Does the hose actually do something beside hold up that wiring?

It does 2 things

1. Holds up the wiring
2. Holds the sensor in place at about 10 o clock (keeps it from spinning)

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[HeatXfer]

I really think the reason the hose is not available by itself from Ford is that they believe the fan assembly is failing or has failed and pulls hose apart. Ford has used this system on other models for quite a few years meaning the hose and the issue is probably the design of the assembly used by Ford on the Ranger. I would bet that when you replace with new assembly the problem would never happen again as it is updated. Same reason they have not recalled other defective systems, they just replace the ones that break under warranty.

Yep, that seems a likely reason.

 

[airline tech]

I do not think the Fan clutch locking up would do it. Best guess... Sensor binding on the shaft would. Hose too pliable. flexible, to keep the sensor from axial play would assist in binding. Low quality hose that can't handle the occasional bind and begins to deteriorate magnifies the problem.

So I suspect a little bit of both. It doesn't take a catastrophic failure of either to see this happening. Once that sensor is not being held perpendicular to the shaft binding can occur.

Once the hose deteriorates from constant flex st the stress points, the sensor is allowed to float just a little too freely allowing axial movement. Then it is just a matter of time before the cable is pulled just enough to catch on something, and BANG! The deed is done.

Note the last incident. The cable was rubbed through to the copper, and never wrapped. It was laying on the spinning shaft just enough.

That's my theory, and it is why I went with a beefed up reinforced hose. I want to minimize axial play, keeping that sensor plate as 90 degrees to the shaft.

If mine blows up we will know that my assumption was incorrect. I should check under the hood!

One last thought. Since I changed out the hose I seem to hear the clutch engaging more at higher speed (the fan speed not the truck speed) than before. Could be that I am more sensitive and listening for it now. But it seems to activate more often. It still gradually spins up and down.

This is true, but wanting detail on - (A Failure) (Of What?) Hose or Fan?
Which one is the Root Cause per this Tech who he was communicating with?
This is most likely going to be his opinion but curious on his response to the question.
That’s all (curiosity)

 

[TJC]

This is true, but wanting detail on - (A Failure) (Of What?) Hose or Fan?
Which one is the Root Cause per this Tech who he was communicating with?
This is most likely going to be his opinion but curious on his response to the question.
That’s all (curiosity)

I get it. Thanks for the clarification.

Just took another quick look at mine and it is exactly as I left it.... which proves nothing, except that what I did isn't hurting anything. It may not have ever failed. But I do feel better that I strengthened that hose. It was absolutely flimsy.

 

[pboggini]

I went out and looked at mine this morning. All seems well so far.
But I am now a bit paranoid about it.

This was me a couple of months ago when I saw this. As you can see from my post back then I went out to put a safety cable in place just in case when the hose broke off in my hands. So, I had to take action that day.

I highly recommend looking into replacing this hose before it breaks.

 

[TJC]

I honestly think the hose is the issue, not the sensor. But I've been wrong before.

I also believe it is better to be a little paranoid and correct the problem, than to let it go and find yourself stranded with a big service bill. It is a relatively easy fix. Of course this is coming from a fellow who is prefers to anticipate and be ahead of the curve.

 

[RangerBill]

I honestly think the hose is the issue, not the sensor. But I've been wrong before.

I also believe it is better to be a little paranoid and correct the problem, than to let it go and find yourself stranded with a big service bill. It is a relatively easy fix. Of course this is coming from a fellow who is prefers to anticipate and be ahead of the curve.

I also believe that the hose deteriorating is the problem because mine used to be very flexible on the ends, but now is hard. So far, it hasn't broken.

 

[TJC]

Things move slowly... until they don't! This holds true for material failures.

 

[HotPepperRedRanger]

Since, this issue is not 100% confirmed by a Ford Tech. ask for specifics on this.

1. Is the support hose (the root cause) (Breaking Down - Heat and Wear)

or

2. Does the Fan Clutch, Fail and Lock up and create extra tension on the Hose

or

3. A combination of both

As I am trying to determine, if you disconnect the hose or it is broken
Some are staying in place and only requires the hose to be repaired (Modified) and some are
being twisted down (pulling) the harness down with it - hitting the pulley bolts, and then the catastrophic (Ripping) the harness apart.

I have not figured out what is causing the twisting (rotation) of the module, is it actual Fan Clutch Failure or just (flip a coin) if the hose breaks and the module just happens to catch the back side of the hub.

Picked up the truck today after parts back order for a week. Confirmed with the Ford technian that it was a hose failure.

 

[Big Blue]

Picked up the truck today after parts back order for a week. Confirmed with the Ford technian that it was a hose failure.

Typical non-answer! Did they have to replace the fan assembly or not. Still don't know what caused the hose to fail. Was it degradation due to heat or excessive tension.

Just looked at my 2019 again today. Still pliable and looking good. Of course I only have 37K on it so not as many heat cycles as some of you.

 

[HotPepperRedRanger]

Typical non-answer! Did they have to replace the fan assembly or not. Still don't know what caused the hose to fail. Was it degradation due to heat or excessive tension.

Just looked at my 2019 again today. Still pliable and looking good. Of course I only have 37K on it so not as many heat cycles as some of you.

Yes they replaced fan due to wiring being loose and going to fan. The hose failure seems to be caused by heat. Original hose was very brittle, and fan was nicked and damaged but still functional.

 

[airline tech]

Well at least it appears that the question is answered- Hose Failure - Root Cause and in the right scenario of module position- it grabs and rotates and if if rotates far enough- the harness is pulled down to the bolt heads - then this action rips it apart.
So at minimum we need to include this hose inspection at regular intervals or preventive action and modify it.
My is factory as of now, but if the hood is opened - I check it

 

[TJC]

I think it is a waterfall type failure. You won't necessarily see it coming unless you are proactive. I had to stretch my hose to see the light cracks. Didn't see them without tugging on it a bit. Look at the engine stud about I" from the hose end, just past the bump in the hose for the cracks..

 

[HeatXfer]

Reviving this thread for an FYI: I replaced the stock fan sensor hose with some high pressure fuel line that I stiffened with short length of soft-drawn copper tubing. Since this thread began, I've wondered what the start-up torque was on that hose and what it was while running. I pulled the stock hose a set a Newton force meter in it's place. I thought it would be negligible, but y'all can decide for yourself.

At approx 50grams of force on the senor stub, it looks to be about .22 in-lbs. IMO it's heat, vibration and rot that causes the failure, not the stress from torque.

(This pic links to imgur)

 

[airline tech]

Reviving this thread for an FYI: I replaced the stock fan sensor hose with some high pressure fuel line that I stiffened with short length of soft-drawn copper tubing. Since this thread began, I've wondered what the start-up torque was on that hose and what it was while running. I pulled the stock hose a set a Newton force meter in it's place. I thought it would be negligible, but y'all can decide for yourself.

At approx 50grams of force on the senor stub, it looks to be about .22 in-lbs. IMO it's heat, vibration and rot that causes the failure, not the stress from torque.

(This pic links to imgur)

AWESOME - T-Shooting - Information
And this appears to back up the conclusion thus far - the Clutch Fan itself is not failing or wearing it's the hose deterioration.
Now it is still possible for some wear creating some extra rotational stress but with - Thus far no major reports of any failure codes or issues with the Clutch Fan itself, tells me that it is a solid reliable part and the only reports that I recall seeing of codes or issues shows the hose broken and with your (TEST) it clearly shows that the hose does see a fair amount of stress applied against it.
So, with that (if the hose was a better quality) then we would most likely not see the issues that we have.


Thanks for the extra step?

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