Defroster question

[Glen Davis]

The defroster’s in my 1989 J model are not working. I thought the problem was the ducks were missing, so there was no way for hot air to get to the windows.  The shop said this:

“Defrost INOP.
Corrective Action:
Re-rigged small "wire" from butterfly valve to limit switch. Ops ck good, however blower motor is very loud.”  I haven’t picked up the plane or spoken to them yet to ask any questions but why would a defrost valve have a limit switch? And, if you have a blower on your defrost is it very loud?

 

[PT20J]

It’s not a limit switch. The defroster butterfly activates a microswitch via a piece of wire. The microswitch turns the blower on and off as the door is opened and closed. The wire can become detached from the microswitch and then the blower won’t run.

Noise is relative. You’ll have to listen to it to determine if it’s just the air moving or if a bearing is going bad.

Skip

[Glen Davis]

Wow.  PT20J, you never ceases to amaze me. And your willingness to help and share… priceless.  Thank you. 

[Ethan]

How can I get a blower motor in my M20K. The worst thing for me is shoe-horning four people in the airplane on an cold and early morning, than constantly wiping the inside of the windshield so I can see out. My defrost has no blower, it just uses airspeed and ram-air pressure but I sure would love to have a defrost motor!

[PT20J]

13 minutes ago, Ethan said:

How can I get a blower motor in my M20K. The worst thing for me is shoe-horning four people in the airplane on an cold and early morning, than constantly wiping the inside of the windshield so I can see out. My defrost has no blower, it just uses airspeed and ram-air pressure but I sure would love to have a defrost motor!

I'd check the IPC for the correct part number (it was an option on some models/years) and then check the salvage places.

[PeteMc]

20 minutes ago, Ethan said:

The worst thing for me is shoe-horning four people in the airplane on an cold and early morning, than constantly wiping the inside of the windshield so I can see out.

You let them breath?!  There's your first problem I never let people breath in my K if the windows start to fog up!   

But I totally agree with you that it can be a big issue.  Luckily I haven't done too many flights were the inside fogs up before we get going.  I saw one guy that had a Cig Lighter Clip Fan that he clipped to the glare shield and pointed at the window during taxi and then just got rid of it when he was cleared for TO.  Apparently worked well and might be easier than adding a defrost blower to the K. 

[Hank]

2 hours ago, PeteMc said:

 I saw one guy that had a Cig Lighter Clip Fan that he clipped to the glare shield and pointed at the window during taxi and then just got rid of it when he was cleared for TO.  Apparently worked well and might be easier than adding a defrost blower to the K. 

I have a little one that runs on a USB cord. Plug it into your phone, tablet, laptop or battery pack.

 

[PeteMc]

8 minutes ago, Hank said:

I have a little one that runs on a USB cord.

Does it work well?  I should have realized by now there would be USB fans (Duh!) and just did a quick search and found a lot of them.

In the past it hasn't been an issue, but since I've moved this has got me thinking. 

ALSO... They're great in the summer to just get a little air moving in the cabin while on the ground.

 

[Hank]

I plug it into my phone for "personal cooling."

My C has a valve on each side to block off the heating ducts and become a defroster, which I've never used even in West-by-Gawd, Virginny for my first 7 years of ownership.