M20J MSE Clock Lighting

[pjsny78]

I have a problem that I am hoping someone can help me with. I have a 95 Mooney M20J MSE. My question has to do with the stock clock on the left side of the panel. When I bought this plane it has never lit up. It is virtually useless at night to me and I do a lot of night flying. I like the clock and want to keep it but I need it to light up. Does anyone know if there are light bulbs inside of the unit? My avionics guy says it would be a waste of money to pull it out, check to see if the unit is lighted, if it is lighted to then order the bulb, and then redo the process if they can get the bulb.  Does anyone have any information on this? I would really appreciate it.

 i hope you can make out the clock in the picture.

 

[N601RX]

Before going to the trouble taking it out I would look and carefully trace the wiring diagram to familiarize myself with the wiring to the clock. If the clock works fine it almost sounds the wire for the lighting is at fault or a fuse somewhere. I had a similar situation and found a fuse for that circuit back near the battery! Without the wiring diagram I would have never known to look for that fuse back there.

AND I'M NOT MIKE I'M PK!! Aka allsmiles!

[Cris]

Davtron Inc. makes a nice modestly priced digital replacement like their mdl M800. It is essentially plug & play and and at $150 or less is probably less expensive than a mechanic troubleshooting.

[PTK]

If you do end up replacing you may also want to look at the M802 from Davtron. I was actually looking for a clock to replace the old Mooney analog clock with the hands. I wanted one that always shows GMT and local time. I called Davtron and they had this brand new product. We worked out an arrangement for me to test it! I can tell you it's awesome. GMT and local time always displayed in a very slick LCD display. It ofcourse has all the feautures you'd ever want in an aviation chronometer as well.

But take a look at the wiring diagram as I said. It may be something as simple as a wire or an inline fuse somewhere. 

[RJBrown]

Problem with replacement is your clock does not have a standard round hole.

I had a round Analog clock standard in my 1990 MSE. The time adjust knob was broken. I replaced it with a Electronics International SC-5 clock.

Changed it myself and had it signed off. Not hard to get to at all. Be careful about what you buy there is very little depth behind the panel in that area. Check dimentions first before you buy. Lines to the back of my AI had to be changed by Arapahoe Aero before I could complete the install.

Do you know what brand the clock is? The information you seek would come from the clock supplier. Any bulb would most likly be 24 volts and that makes it harder to find.

Pull the glareshield and take a look. That alone might answer your questions.

[Hank]

A quick fix is to spend ~$20 with Aircraft Spruce for an ashlight. This has four red LEDs and replaces the ashtray to your left. It provides enough light to write on my kneeboard even with everything else shut off.

[kortopates]

Shocking to see so much banter about replacing the clock to poetntially solve replacing a bulb.

Most/many clocks use their own batteries for the clock, (hence why they work all the time with out ship power), and are wired to the electrical system for lighting. Find out your clock model and search the manufacturer website (or current manufacturer/owner) for an installation drawing of the clock that will tell you if is lighted and the bulb used if so. Not all are lighted or have the option installed. Then with the proper data, you can troubleshoot the problem and find a new bulb if necessary. You shouldn't need to replace the clock unless you really want too.

[jetdriven]

I will bet you can find some 28v grain of wheat bulbs in there. Spruce has them for   A hangar fairy can change them. Or you can pay a shop 200$ to do it for you.   Here is a similar model.

https://picasaweb.google.com/107511494982148541935/Davtron_803_clock_timer

 

bulbs: http://www.aircraftspruce.com/catalog/inpages/grainowheatbulb.php

 

 

 

 

[pjsny78]

thank you everyone for all the recomendations. i really do appreciate it and will be taking your advice.

thanks again.

[pjsny78]

Would anyone know of what the part number is for the wheat bulbs in this particular clock are? I have called many people and MSC'S to get this information to no avail. I have e-mailed the Mooney factory countless times and never heard back. If anyone would happen to know please let me know as I would really appreciate it.

[jetdriven]

Just get them from aircraft spruce.  You can fix it that way

[pjsny78]

Unfortunately aircraft spruce seems to only sell one type of wheat bulb. I need the correct P/N or it could potentially burn out the plastic if it is not the right type as there are many differnet types of bulbs. If anyone knows of anything please let me know. I have been trying for months to find this P/N to no avail.

[Awful_Charlie]

I've just had the same problem on my Bravo.  The clock is a VDO unit, re-badged by Mid-Continent, and you need one of these: http://www.google.com/products/catalog?q=osram+bulb+12/1.2&hl=en&client=firefox-a&hs=9cD&rls=org.mozilla:en-GB:official&prmd=imvnsfd&psj=1&bav=on.2,or.r_gc.r_pw.r_cp.,cf.osb&biw=1272&bih=851&um=1&ie=UTF-8&tbm=shop&cid=6693938332104088383&sa=X&ei=qZQgT_iIK4qssAae-JD8Bw&ved=0CGoQ8wIwAg

Ben

[pjsny78]

Ben,

you are the best. thank you so much i cannot tell you how much i appreciate this.

 

thank you......

[Awful_Charlie]

My pleasure - and even better, the cost shouldn't break the bank either!

[Costa Leite]

Ben and Pjsny78,

I have the exact same clock light problem on the 1998 M20J Allegro. 
I was never able to solve this problem despite several contacts with Mooney Factory that told me they were still waiting for a Mid-Continent answer. 
I just searched today at MooneySpace for this situation and found this present Topic and it seems you have the solution! But the shared link in 2012 is no longer working... can you please help?

I would like to know if this original clock can be illuminated, and if so what part/change do I need to get?

Many thanks in advance for your help!

Regards

Fredi

[Costa Leite]

On 1/25/2012 at 7:06 PM, Awful_Charlie said:

My pleasure - and even better, the cost shouldn't break the bank either!

Ben,

I have the exact same clock light problem on the 1998 M20J Allegro. 
I was never able to solve this problem despite several contacts with Mooney Factory that told me they were still waiting for a Mid-Continent answer. 
I just searched today at MooneySpace for this situation and found this present Topic and it seems you have the solution! But the shared link in 2012 is no longer working... can you please help?

I would like to know if this original clock can be illuminated, and if so what part/change do I need to get?

Many thanks in advance for your help!

Regards

Fredi

[LANCECASPER]

@Costa Leite This thread should help. Go to your local Audi or Porsche dealer or look online for the part number 431-919-040. Since you're in Germany it should be easy. (Same clock as in a Porsche 944)

 

 

Here are some pictures of your clock to make it easier to see how the bulb is replaced:

[jcovington]

3 hours ago, Costa Leite said:

have the exact same clock light problem on the 1998 M20J Allegro. 
I was never able to solve this problem despite several contacts with Mooney Factory that told me they were still waiting for a Mid-Continent answer. 
I just searched today at MooneySpace for this situation and found this present Topic and it seems you have the solution! But the shared link in 2012 is no longer working... can you please help?

The bulb part number is OSRAM 2721MF8 which is a 12V 1.2W bulb. Be sure to order the exact part number as some of the bulbs that cross to the OSRAM bulb have a slightly different base and won't fit. The bulbs were pretty hard to find in 2017 and I ended up ordering a box the last time I found them.

The first time the bulb failed I contacted Mid-Continent and they sent me a bulb for free. I didn't try that the second time it failed as I had the part number.

The easiest way to replace the bulb on a J model is to loosen the ASI screws and push the ASI back. At that point you can reach in and access the bulb through the ASI hole. It is is a 1/4 turn to remove and replace the bulb. It is fairly stiff to remove as the bulb is a friction fit and the contacts are made using small spring clips. I have used forceps in the past to get enough grip to remove the bulb. Don't try to loosen the screws and remove the clock. The screws have nuts on the back and are very hard to reach.

Jim

Edited March 31, 2020 by jcovington
Typo fix

[philiplane]

Mooney service centers often have the lamp in stock, they're about $30. It comes with the black plastic holder.

[LANCECASPER]

$1.79 each here   https://www.belmetric.com/instrument-cluster-light-bulbs-c-18_156_189/ob2721mf8-cluster-bulb-p-1141.html

[larryb]

And if you have a 3D printer print this nifty bulb changing tool.

https://www.dropbox.com/s/4a4yxv65ahc1a5s/clock_tool.stl?dl=0

 

[Costa Leite]

Dear All,

Many thanks for all replies and shared knowledge on this issue.

I understood now that the M20J Allegro panel clock is a VDO/Porsche944 unit with P/N 944.641.213.00, re-badged by Mid-Continent, and there are USD50$ Repair Kits (that include LCD screen, Bulb, etc) for these units on-line:

https://www.ebay.com/itm/Porsche-944-968CS-digital-clock-LCD-screen-repair-kit-/122182345640

I probably have a burn bulb, which PN is 431-919-040. For OSRAM the PN is 2721MF8, and it's mandatory to order the exact part number as some of the similar OSRAM bulbs won't fit.

To replace the bulb, "the easiest way on a J model is to loosen the ASI screws and push the ASI back. At that point you can reach in and access the bulb through the ASI hole. It is is a 1/4 turn to remove and replace the bulb. It is fairly stiff to remove as the bulb is a friction fit and the contacts are made using small spring clips. I have used forceps in the past to get enough grip to remove the bulb. Don't try to loosen the screws and remove the clock. The screws have nuts on the back and are very hard to reach." (quoting jcovington)

Instead of using forceps to turn the bulb out, there is a 3D printer file above for a useful tool to use on this service.

I already ordered 2x OSRAM Bulbs from Germany. A very cheap part for an aircraft!!

When I get this service finished I will post the feedback.

Cheers,

Fredi (Mooniac @ Porto, Portugal)

 

Edited April 2, 2020 by Costa Leite

[Costa Leite]

Our Mooney is just coming out from annual inspection, and the clock bulb was changed. 

The mechanic found easier to access the bulb through the top of the panel with the glareshield removed. He didn't attempt to access by the ASI, but I believe this is also a good option for a quick access that avoids removing the glareshield.

I 3d printed the changing tool with the file that Larryb shared above, and it revealed to be very helpful because it takes a lot of pressure to turn the bulb out. Actually, you need to press and turn 90º to take it out. But with all information shared here on MS and also with the web videos (https://www.youtube.com/watch?v=4j5Bg05vLuE) about Porsche 944 clock repair kit, this was a painless job. 

You can see below pictures of the before and after. Our clock really shines now!!!

Thanks a lot to all that helped !!

(I still recall severall emails I changed with MooneyFactory asking for information on how to solve this issue, and reply had always been that they were waiting for the MD answer...!! one more situation where MS is a really powerfull tool for Mooney Pilots)

Cheers

Fredi

[carusoam]

Go MS!

-a-