Original VDO clock with strange behaviour

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Etienne Kerkhoffs
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Original VDO clock with strange behaviour

#1 Post by Etienne Kerkhoffs » Mon Jan 07, 2019 6:33 pm

I have an original 1958 6V VDO clock that worked for years. But last year it stopped. When I pulled the adjustment knob (at the bottom) and pushed it back it started working again. Sometimes for a few hours, but sometimes only for a few minutes. I connected it directly to the battery but no improvement. I removed it from the car and connected it to a 6.5V phone charger. It kept going for days. Then I connected the clock to the (Optima) battery that gave 6.3V and I heard the typical sound of recharging the mechanism inside the clock. But after a few hours it stopped working….. When I disconnect it and connect it again, I hear that sound again and the clock starts ticking again, but only for a limited time. The same result with a normal lead acid battery.

Does anyone know what the problem could be with my clock? I don’t want to convert it to a quartz clock because I like that charge/recharge sound every couple of minutes and the movement of the second hand.

Thanks!
Etienne Kerkhoffs
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Alan Hall
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Re: Original VDO clock with strange behaviour

#2 Post by Alan Hall » Mon Jan 07, 2019 6:59 pm

Certainly not a lot of experience with these clocks, but I believe they use a set of points to actuate the winding mechanism, so it sounds like the points might need cleaning as they apparently are sometimes not making contact so the clock does not wind and stops.

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Re: Original VDO clock with strange behaviour

#3 Post by Etienne Kerkhoffs » Mon Jan 07, 2019 7:08 pm

Thanks for your reaction. I will check the inside and clean it.

Can it be that the reason that the clock does not stop when connected to the 6.5V phone charger is because of a current difference?
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Re: Original VDO clock with strange behaviour

#4 Post by Alan Hall » Mon Jan 07, 2019 7:14 pm

Could be the points are on the verge of passing current and maybe the phone charger has a "ripple voltage" rather than a pure DC voltage that is just enough to cause the points to pass current. Any EE's in the crowd?

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Re: Original VDO clock with strange behaviour

#5 Post by Richard Shilling » Mon Jan 07, 2019 7:27 pm

The points are one possibility. Another is that it's dirty and needs a cleaning. North Hollywood Speedo to the rescue!
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Mike Wilson
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Re: Original VDO clock with strange behaviour

#6 Post by Mike Wilson » Mon Jan 07, 2019 7:38 pm

I have cleaned the mechanisms with electronic cleaner then follow up with watch oil on the moving parts. The points could also need cleaning.

I'm sure there are some videos on how to remove the cover from the rear of the clock.

Mike
Last edited by Mike Wilson on Mon Jan 07, 2019 8:00 pm, edited 1 time in total.
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Re: Original VDO clock with strange behaviour

#7 Post by Etienne Kerkhoffs » Mon Jan 07, 2019 7:48 pm

Thanks! I will take it apart this week and clean it. I will let you know the result.
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Re: Original VDO clock with strange behaviour

#8 Post by PaulLima » Mon Jan 07, 2019 7:57 pm

I have taken apart and fixed many of these VDO clocks. As mentioned above, there is a set of points that close when the clock wind down. They operate a solenoid that winds the clock, which will then run for tens of minutes, then repeat the process. When the clock mechanism is dirty enough, the winding mechanism sticks, the points get hot, and, just like in the distributor, the burn. Many times this will also cause the fusible link to melt, it which case the clock won't run at all. Open the clock (by far the hardest part), burnish the points, and lightly blow out the crap. It the fusible link is burned, you need to replace it (I use a piece of solder) You need a VERY light oil to lube the mechanism. I've used spray teflon (Tri-Flo) with some success.

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Re: Original VDO clock with strange behaviour

#9 Post by Mervyn Hyde » Mon Jan 07, 2019 8:25 pm

Paul is right. I have repaired quite a few of these clocks and they are an imperfect instrument. The points degrade and can burn, the fusible link breaks or the clockwork mechanism gets sticky. Cleaning with a good electronic fast drying cleaner and then using a little, light 'clock oil' (eBay) on the pivots and shafts is a good idea. Fusible links can be easily replaced and points cleaned. I had a bucket of old clocks and found that this was all that was needed with several of them. A small amount of dielectric grease on the points can help preserve their condition. If the clockwork mechanism is damaged and the cogs worn or the rotating spindle off balance there is a need for rebuilding. The coil and its thin contacts can also burn or deform and then needs rebuilding in some cases. Each can have different issues but some are easily salvageable.
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Re: Original VDO clock with strange behaviour

#10 Post by Etienne Kerkhoffs » Mon Jan 07, 2019 9:13 pm

Sounds like a nice job to do. As the clock is still working with the phone charger, I guess that the points are not burned and that the fusible link is not broken. I will post a picture when I have taken the clock apart.
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Re: Original VDO clock with strange behaviour

#11 Post by Etienne Kerkhoffs » Mon Jan 21, 2019 11:25 am

I finally found the time to take the clock apart. The inside mechanism looks very clean. However, I think that the points are a bit rough.
Shall I just clean them and polish them a little bit with fine sandpaper of shall I solder them first to get a bit more material on them?

Thanks.
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Etienne Kerkhoffs
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Re: Original VDO clock with strange behaviour

#12 Post by Wes Bender » Mon Jan 21, 2019 11:43 am

Polish them. Don't put solder on the points or you'll be doing this job again in a few weeks or months..
Some days it just isn’t worth the hassle of chewing through the restraints......

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Re: Original VDO clock with strange behaviour

#13 Post by Mike Wilson » Mon Jan 21, 2019 1:31 pm

One other thing to consider is adding a separate ground wire to the clock. Sometimes the bracket doesn't provide a good ground. I solder a ring terminal that fits over the bracket stud on the clock and the another end has a ring terminal attached to a wiper motor bolt.

Mike
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Re: Original VDO clock with strange behaviour

#14 Post by George Hussey » Mon Jan 21, 2019 2:19 pm

I agree, clean it. My 66 corvette clock does the same thing, as did my 64 riviera clock. Took both out cleaned them and they are fine now


Alan Hall wrote:Certainly not a lot of experience with these clocks, but I believe they use a set of points to actuate the winding mechanism, so it sounds like the points might need cleaning as they apparently are sometimes not making contact so the clock does not wind and stops.
George Hussey

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Re: Original VDO clock with strange behaviour

#15 Post by Ron LaDow » Mon Jan 21, 2019 2:40 pm

Pretty sure you can find it on-line now; there is a dedicated 'clock oil' available which has been developed for the minimal driving torque of spring-powered clocks. Doesn't attract 'stuff' and doesn't gum-up over time.
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