'90 J Electeic Cowl Flaps Not Moving

[Ragsf15e]

1 minute ago, PT20J said:

The schematics are actually part of the Service and Maintenance manual. Chapter 91 at the back of the manual has the part numbers for electrical components. So you find the schematic for your serial number and look up the reference designator for the part you want and then go to the section in chapter 91 for your serial number and find the part number that corresponds to the reference designator. Most will be standard electrical components available from any number of online electrical parts suppliers.

I hadn’t realized that some of the later J models used the Globe motor for their cowl flaps too.  I don’t want to stockpile salvaged parts, but at least there might be more donors available rather than just 252s, Encore and Bravos.  

[Lax291]

50 minutes ago, PT20J said:

Is this a crack in the exhaust?

Drip from oil above thankfully. 

[Lax291]

Wonder if this is a better picture, guessing the hole in the shaft should be aligned with the hole in the bushing and a pin dropped through to secure it?

[PT20J]

The IPC calls for two roll pins and I believe there are two 90 degrees apart, but I've never had to replace them. @kortopates will know.

The solder connections to the top microswitch in the picture look a little funky. Maybe that's the problem.

[kortopates]

The IPC calls for two roll pins and I believe there are two 90 degrees apart, but I've never had to replace them. [mention=7862]kortopates[/mention] will know.
The solder connections to the top microswitch in the picture look a little funky. Maybe that's the problem.

Yes, 2 roll pins 90 degrees apart. from the pict looks like they’ve sheared and the bracket is coming off the end of the shaft. This can be confirmed by exercising the motor with the cowl flap not in the fully open or closed position.
it’ll be lucky if the shaft didn’t break at the outer roll pin hole. That was a common occurrence in the original motors and why they went to a thicker shaft and bigger roll pins after original production.


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[Lax291]

4 hours ago, kortopates said:

Yes, 2 roll pins 90 degrees apart. from the pict looks like they’ve sheared and the bracket is coming off the end of the shaft. This can be confirmed by exercising the motor with the cowl flap not in the fully open or closed position.
it’ll be lucky if the shaft didn’t break at the outer roll pin hole. That was a common occurrence in the original motors and why they went to a thicker shaft and bigger roll pins after original production.


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Thanks, sending photos and feedback to my mechanic. Big question is why did these shear in the first place so I'm sure he'll be looking into that. 

[kortopates]

They have a long history of doing so without any help from just wear but of course you want to make sure the limit switches are working properly.


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[Ragsf15e]

5 hours ago, kortopates said:

Yes, 2 roll pins 90 degrees apart. from the pict looks like they’ve sheared and the bracket is coming off the end of the shaft. This can be confirmed by exercising the motor with the cowl flap not in the fully open or closed position.
it’ll be lucky if the shaft didn’t break at the outer roll pin hole. That was a common occurrence in the original motors and why they went to a thicker shaft and bigger roll pins after original production.


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Once you get new pins in there, I would definitely be checking those limit switches before trusting them to stop the motor!

[Will.iam]

On 12/12/2025 at 8:50 PM, kortopates said:

Electric cowl flaps are wonderful being infinitely adjustable. I would never trade mine for manual cowl flaps. They are problematic even with just 3 positions. Not sure we can blame it on Mooney Speeds but the Rocket owners have even harder time getting them closed before they’re going to fast to do so.

To avoid going back to manual cowl flaps i’d have to upgrade to an Acclaim or Ovation that doesn’t have cowl flaps!

You may well have found something where your Cessna is superior to the Mooney since the Mooney manual cowl flaps give a lot of grief to pilots.


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That is only because the cessna is so slow there is not enough wind to blow the cowl flaps closed. Superior cowl flap control does not offset crappy speed performance in my book.  

[Lax291]

I lucked out as it was only the roll pins that broke and needed replacing.  Motor, shaft, and micro switches were all in great shape. They did have to tighten some hardware that loosened up and straighten the cowl flap actuator arm micro switch stops, but all is working well. 
 
He mentioned the new roll pins were loose in the holes so he safety wired them in place. Appreciate the help from the group and happy it was a relatively simple fix.