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[How To] 1.0 Fiesta A/C Clutch Replacement

911 Views 4 Replies 3 Participants Last post by  wpomeroy
Hello Everyone!

I looked all over for this, and didn't see it anywhere, so I thought I'd do a quick write up. I was driving home from an errand the other day and quite suddenly I lost all of my air conditioning on my 2015 1.0 Ecoboost Fiesta. After quite a lot of investigation, I tracked it down to the A/C clutch field coil. The smoking gun (other than an electrical burning smell when it went out) was measuring the resistance across the field coil. It should be between 3 and 5 ohms. Mine was infinite. You can find the field coil connector (measure across the two pins on the connector) by finding the coil, and tracing the pigtail off the coil up on the front of the compressor (on the side facing the radiator).

Once you have determined that your A/C clutch is bad, the part you need to order is:


Everywhere I looked, it ran from ~$210 to $300, so I ordered the one closest to me which was also conveniently the cheapest. The part came in very quickly.

It's of utmost importance to note that the factory service manual says to REMOVE the A/C compressor to service this clutch. this is ABSOLUTELY NOT necessary as you will see in the photos on this.

The steps are as follows.

Raise the car somehow (I used rhino ramps)

Remove the two Flathead/Torx screws that hold the accessory belt splash shield in place and set the splash shield aside.

Remove the accessory belt. The accessory belt is tensioned with the belt tensioner (shocker), but taking the tension off requires a 1/2" socket driver (the square head -- this is typical for tensioners). Remove the belt off the tensioner, wrestle the driver off which is made more annoying as the belt and driver like to interfere with each other. Leave the accessory belt on the crank pulley, it'll stay out of the way.

Remove the 8mm bolt that holds the front of the A/C clutch on. Refer to the feeler gauge photo to see the bolt. You'll need to hold the clutch piston to prevent it from rotating.

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Remove the Piston, note the shim in the cavity on the back side of the piston. You won't need this, but it's a good reference.

You'll have now exposed the clutch face. This is removed with a simple snap ring removal, and slides off with a little convincing. This will expose the coil. Be careful with the snap ring pliers such that you do not marr the bearing seal. It's an expensive bearing, and you want it to last.

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My coil had obvious signs of burning, from what appeared to be an internal short and a thermal event causing the whole thing to go kaputt.

Remove the snap ring holding the coil on. This one is more of a pain in the neck. It's the copper colored snap ring. Stick with it and you'll get it. Remove the coil, noting that it has a locating tab on the back of the coil to control the rotation of the coil. You'll need to position this on the way back in correctly.

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Unplug the pigtail of the clutch, and remove the connector from the standoff by sticking a small flathead or pick behind the connector and pulling. It's a bit of a pain, but these connectors usually are.

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Reassembly is quite simple, in the reverse order of disassembly.

Install the new coil and pigtail onto the old standoff. Pay careful attention to the rotation of the coil, as you won't be able to install the snap ring if it is not seated.

Install the new pulley / clutch. This one takes a bit of a careful hand, as if you put it on crooked, it doesn't want to go on. Proper alignment and it will slide right on.

Fasten the pulley with the new black snap ring.

You're now ready for the trial and error of shimming the A/C clutch. The spec for this is 0.02-0.03 inches (it's the same for all fords I think).

The clutch and pulley kit comes with an assortment of shims, you'll be best served by organizing these and using your brain here. The ford kit comes with 7 shims, in 0.1mm increments, starting at 0.7mm.

The shims included are 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, & 1.3mm

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I selected the 1.0mm shim and installed it. Tighten the new bolt down, but no need to torque, just bottom it out. Measure the air gap with a feeler gauge in 3 places and adjust shimming as needed. An air gap too small will require a larger shim. A worn out A/C clutch will require a smaller shim. I ended up using the 1.2mm shim, which put my air gap right at 0.025 inches. My old A/C clutch (which had 125,000 miles) had a measured gap of 0.022, so I am not very concerned about wear.

Do your best to torque down the bolt once you get the system assembled, but PLEASE note that the bolt is quite delicate. DO NOT use an impact to drive it in, because you most likely break the head off the bolt and have to drill it out.

Torquing down the bolt may require the removal of the intake hose. Be warned, if you have a higher mileage fiesta like mine, there may be some oil buildup in the bottom of the intercooler. Don't be surprised, and don't be too alarmed.

I used an electric impact on mine, and I thought I was being careful, and I sheared the head off the bolt and got to break out my left handed drill bit to remove the broken bolt shank from the inside of the compressor. It was not fun.

Once you complete this, you're ready to put the belt on, replace the splash shield, and enjoy that cool, cool air conditioning.

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Please let me know if you have any questions.


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Awesome how-to. Thanks for sharing! I hope that I never need this, but it's nice to know it exists.
Awesome how-to. Thanks for sharing! I hope that I never need this, but it's nice to know it exists.
Of course! The important things I wanted to highlight were:

1. You don't have to take the compressor out of the car
2. The kit comes with shims, and they're well thought out
3. Be really careful with the clutch bolt and to NOT use an impact, even a small electric one.

For me, the failure mode on this was very sudden, and quite bizarre. I've noticed that on these fiestas, the supplier part quality is really lacking. Mine had a weak starter from the factory (always slow cranked, finally failed, a new OEM starter cranked faster than it ever had), a bad clutch master cylinder (at the pedal), and now an A/C clutch coil failure. Those are all things that should be checked out more thoroughly from the factory. The A/C clutch coil was after 7 years of manufacture which is more forgivable, but I suspect a manufacturing defect finally reared its head.
Great write up! Thank you. Btw, wonder if the clutch failure triggered a code?
Great write up! Thank you. Btw, wonder if the clutch failure triggered a code?
Hey! No, it did not cause a single code, just blown out A/C. I had to measure the resistance across the coil to diagnose the blown out circuit.
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