Save the clock tower ... Back to the 56

[klogsdonjr]

Anyone have a pic of the back of their clock?

My clock has not worked since i acquired the car. It's getting towards the top of my list to at least do some forensics. There are a few good sites that show how to troubleshoot and try and bring it back to life.

From under the dash I see the bulb socket towards the upper middle of the clock. I see two outer screws, one on the left and one on the right. The left one has a black wire attached by eyelet with a nut, and it seems to be ground at the top of the dash and splits over towards another accessory to the left. I'm assuming this is ground. What I don't see it a positive wire coming into the clock. I'm wondering if it was disconnected in the past.

I have a wiring diagram that shows 12v power wire shared in line with the lighter. But it's not clear to me where it's supposed to attach to the clock? Can't seem to find a pic anywhere that shows it all hooked up.

Any thoughts?

[ICON 1956]

According to the 1956 wiring diagram from ctci member Leo Affi # 14003 there is only ONE wire connecting Blue-Black band.
Remember to use the "search" engine to find what your looking for.....
http://www.vintagethunderbirdclub.net/p ... hp?t=12023

[paul2748]

I had mine converted to a quartz movement 10 years ago - no problem since. It still "runs like a clock"

[klogsdonjr]

Yes @ICON I saw that post. What it doesn't show is the clock wired up. Would live to see a pic of the back with it all wired up.

[ICON 1956]

Found this picture it suppose to be the back of the clock on a 1956 Bird.I hope this helps:

[klogsdonjr]

Thanks but this doesn't match my clock, nor the clock in the link above. You can see there's no large hole for the light. BUT this pic does have a clear power lead to it and attached to the middle of the clock- that is what I was expecting on mine and didn't see. I only have a black wire attached to the side screw ( which I think is ground).

This pic is different enough tho that I would still want to see one that matches wired so I can understand where the 12v power goes to.

[klogsdonjr]

for posterity sake, 3 really good clock links:

https://fordthunderbirdforum-websitewor ... b377d4.pdf

https://www.oldcarsweekly.com/features/ ... -car-clock

https://forums.fordthunderbirdforum.com ... pair.6980/

[voltron]

For what it's worth I had a '56 Motochron clock apart years ago and saw that it had a transistor inside it which appeared to make a simple voltage regulator circuit that that reduced 12 volts to 6 volts. Transistors are easily damaged if the polarity is reversed. Such as a clock from a '56 being installed in a positive ground '55.

[T-Bird Bob]

There was an article once in a T-Bird Magazine.
I have only this scan.
It might give you an Idea about what to clean and to see if the wires are all ok and if the coils are grilled.
Good luck!
Bob

[klogsdonjr]

Thanks Bob. Yes that is one of the links I posted above.

Still waiting to see if anyone has a pic of the back of their clock with power attached. I'm surmising at this point that the power lead attaches under one of the two nuts on the middle of the back of the clock (similar to the pic ICON shared). But want to confirm with a pic.

[T-Bird Bob]

Hello Klogsdonjr,
I think the only thing that makes sense is the connection on one of those bolts.
That little metal strip just connects the housing to the other bolt.
So your 1956 is a 12V negative ground car. So the power (positive) should be cocnected to the bolt with the "+".
The small metal strip connects the housing of the clock to the bolt with the Minus "-" .
The housing then closes the ground loop via the metal dash/body to the battery.
What I am unsure about is the question of 6V vs 12V? Did ford put a resistor somewhere? Is the clock different (Internal resistors, different wires and coils)?
This is something I can't help with.
Good luck!
Bob

[klogsdonjr]

Bob, brilliant thought. The more I look and listen the more I learn. I hadn't noticed the pic shows a positive and negative symbol. I plan to look for the missing wire this weekend and pull the clock out. I have a much better understanding from your input!

[289ace]

As T-bird Bob said, I would think the ground would be through the clock case and then into the dash. In case it helps, I took some pics of my August '57 car and they are below. Not sure if they are what you need or if 12V '56 system was the same.

[klogsdonjr]

Thanks for taking the time to take and post the pics Ace. As you can see in your pics, the 57 was made by Borg rather than Motochron. And it didn't have a light bulb socket. But it's pretty apparent at this point that the power wire attaches to a screw and nut on the back.

The 56 likely should be on the positive post (will confirm if I can get mine going) and may have a resistor to drop the 12v to 6v for the clock.

The 55 connected to the negative post and is 6v.

At least that is what I think I know at this point

[klogsdonjr]

Requiring a little more contortion than before, now that I have the AC in, I was able to extract the Motochron clock from the 56.

I can confirm it is negative ground and 12v. And likely power wire should go to the positive post on the back.

You can also see in the next pic that there is a manual speed adjuster at the top of the clock face. I had read that some clocks would synch speed as you made initial adjustments to the clock time via the stem. Over time it would adjust the speed depending on how much you changed the time. Don't know if that holds for these or not.

I was not able to find the power lead lying around in the dash. But did find an open slot in the wire going to the map light. It has power so I may try that as my source once I get a wire.

I'll pull it apart and clean per the links above and let you know how it goes.